Modules/datetimemodule.c

/*  C implementation for the date/time type documented at
 *  http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage
 */

#include "Python.h"
#include "modsupport.h"
#include "structmember.h"

#include <time.h>

#include "datetime.h"

/* We require that C int be at least 32 bits, and use int virtually
 * everywhere.  In just a few cases we use a temp long, where a Python
 * API returns a C long.  In such cases, we have to ensure that the
 * final result fits in a C int (this can be an issue on 64-bit boxes).
 */
#if SIZEOF_INT < 4
#	error "datetime.c requires that C int have at least 32 bits"
#endif

#define MINYEAR 1
#define MAXYEAR 9999

/* Nine decimal digits is easy to communicate, and leaves enough room
 * so that two delta days can be added w/o fear of overflowing a signed
 * 32-bit int, and with plenty of room left over to absorb any possible
 * carries from adding seconds.
 */
#define MAX_DELTA_DAYS 999999999

/* Rename the long macros in datetime.h to more reasonable short names. */
#define GET_YEAR		PyDateTime_GET_YEAR
#define GET_MONTH		PyDateTime_GET_MONTH
#define GET_DAY			PyDateTime_GET_DAY
#define DATE_GET_HOUR		PyDateTime_DATE_GET_HOUR
#define DATE_GET_MINUTE		PyDateTime_DATE_GET_MINUTE
#define DATE_GET_SECOND		PyDateTime_DATE_GET_SECOND
#define DATE_GET_MICROSECOND	PyDateTime_DATE_GET_MICROSECOND

/* Date accessors for date and datetime. */
#define SET_YEAR(o, v)		(((o)->data[0] = ((v) & 0xff00) >> 8), \
                                 ((o)->data[1] = ((v) & 0x00ff)))
#define SET_MONTH(o, v)		(PyDateTime_GET_MONTH(o) = (v))
#define SET_DAY(o, v)		(PyDateTime_GET_DAY(o) = (v))

/* Date/Time accessors for datetime. */
#define DATE_SET_HOUR(o, v)	(PyDateTime_DATE_GET_HOUR(o) = (v))
#define DATE_SET_MINUTE(o, v)	(PyDateTime_DATE_GET_MINUTE(o) = (v))
#define DATE_SET_SECOND(o, v)	(PyDateTime_DATE_GET_SECOND(o) = (v))
#define DATE_SET_MICROSECOND(o, v)	\
	(((o)->data[7] = ((v) & 0xff0000) >> 16), \
         ((o)->data[8] = ((v) & 0x00ff00) >> 8), \
         ((o)->data[9] = ((v) & 0x0000ff)))

/* Time accessors for time. */
#define TIME_GET_HOUR		PyDateTime_TIME_GET_HOUR
#define TIME_GET_MINUTE		PyDateTime_TIME_GET_MINUTE
#define TIME_GET_SECOND		PyDateTime_TIME_GET_SECOND
#define TIME_GET_MICROSECOND	PyDateTime_TIME_GET_MICROSECOND
#define TIME_SET_HOUR(o, v)	(PyDateTime_TIME_GET_HOUR(o) = (v))
#define TIME_SET_MINUTE(o, v)	(PyDateTime_TIME_GET_MINUTE(o) = (v))
#define TIME_SET_SECOND(o, v)	(PyDateTime_TIME_GET_SECOND(o) = (v))
#define TIME_SET_MICROSECOND(o, v)	\
	(((o)->data[3] = ((v) & 0xff0000) >> 16), \
         ((o)->data[4] = ((v) & 0x00ff00) >> 8), \
         ((o)->data[5] = ((v) & 0x0000ff)))

/* Delta accessors for timedelta. */
#define GET_TD_DAYS(o)		(((PyDateTime_Delta *)(o))->days)
#define GET_TD_SECONDS(o)	(((PyDateTime_Delta *)(o))->seconds)
#define GET_TD_MICROSECONDS(o)	(((PyDateTime_Delta *)(o))->microseconds)

#define SET_TD_DAYS(o, v)	((o)->days = (v))
#define SET_TD_SECONDS(o, v)	((o)->seconds = (v))
#define SET_TD_MICROSECONDS(o, v) ((o)->microseconds = (v))

/* Forward declarations. */
static PyTypeObject PyDateTime_DateType;
static PyTypeObject PyDateTime_DateTimeType;
static PyTypeObject PyDateTime_DateTimeTZType;
static PyTypeObject PyDateTime_DeltaType;
static PyTypeObject PyDateTime_TimeType;
static PyTypeObject PyDateTime_TZInfoType;
static PyTypeObject PyDateTime_TimeTZType;

/* ---------------------------------------------------------------------------
 * Math utilities.
 */

/* k = i+j overflows iff k differs in sign from both inputs,
 * iff k^i has sign bit set and k^j has sign bit set,
 * iff (k^i)&(k^j) has sign bit set.
 */
#define SIGNED_ADD_OVERFLOWED(RESULT, I, J) \
	((((RESULT) ^ (I)) & ((RESULT) ^ (J))) < 0)

/* Compute Python divmod(x, y), returning the quotient and storing the
 * remainder into *r.  The quotient is the floor of x/y, and that's
 * the real point of this.  C will probably truncate instead (C99
 * requires truncation; C89 left it implementation-defined).
 * Simplification:  we *require* that y > 0 here.  That's appropriate
 * for all the uses made of it.  This simplifies the code and makes
 * the overflow case impossible (divmod(LONG_MIN, -1) is the only
 * overflow case).
 */
static int
divmod(int x, int y, int *r)
{
	int quo;

	assert(y > 0);
	quo = x / y;
	*r = x - quo * y;
	if (*r < 0) {
		--quo;
		*r += y;
	}
	assert(0 <= *r && *r < y);
	return quo;
}

/* ---------------------------------------------------------------------------
 * General calendrical helper functions
 */

/* For each month ordinal in 1..12, the number of days in that month,
 * and the number of days before that month in the same year.  These
 * are correct for non-leap years only.
 */
static int _days_in_month[] = {
	0, /* unused; this vector uses 1-based indexing */
	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

static int _days_before_month[] = {
	0, /* unused; this vector uses 1-based indexing */
	0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
};

/* year -> 1 if leap year, else 0. */
static int
is_leap(int year)
{
	/* Cast year to unsigned.  The result is the same either way, but
	 * C can generate faster code for unsigned mod than for signed
	 * mod (especially for % 4 -- a good compiler should just grab
	 * the last 2 bits when the LHS is unsigned).
	 */
	const unsigned int ayear = (unsigned int)year;
	return ayear % 4 == 0 && (ayear % 100 != 0 || ayear % 400 == 0);
}

/* year, month -> number of days in that month in that year */
static int
days_in_month(int year, int month)
{
	assert(month >= 1);
	assert(month <= 12);
	if (month == 2 && is_leap(year))
		return 29;
	else
		return _days_in_month[month];
}

/* year, month -> number of days in year preceeding first day of month */
static int
days_before_month(int year, int month)
{
	int days;

	assert(month >= 1);
	assert(month <= 12);
	days = _days_before_month[month];
	if (month > 2 && is_leap(year))
		++days;
	return days;
}

/* year -> number of days before January 1st of year.  Remember that we
 * start with year 1, so days_before_year(1) == 0.
 */
static int
days_before_year(int year)
{
	int y = year - 1;
	/* This is incorrect if year <= 0; we really want the floor
	 * here.  But so long as MINYEAR is 1, the smallest year this
	 * can see is 0 (this can happen in some normalization endcases),
	 * so we'll just special-case that.
	 */
	assert (year >= 0);
	if (y >= 0)
		return y*365 + y/4 - y/100 + y/400;
	else {
		assert(y == -1);
		return -366;
	}
}

/* Number of days in 4, 100, and 400 year cycles.  That these have
 * the correct values is asserted in the module init function.
 */
#define DI4Y	1461	/* days_before_year(5); days in 4 years */
#define DI100Y	36524	/* days_before_year(101); days in 100 years */
#define DI400Y	146097	/* days_before_year(401); days in 400 years  */

/* ordinal -> year, month, day, considering 01-Jan-0001 as day 1. */
static void
ord_to_ymd(int ordinal, int *year, int *month, int *day)
{
	int n, n1, n4, n100, n400, leapyear, preceding;

	/* ordinal is a 1-based index, starting at 1-Jan-1.  The pattern of
	 * leap years repeats exactly every 400 years.  The basic strategy is
	 * to find the closest 400-year boundary at or before ordinal, then
	 * work with the offset from that boundary to ordinal.  Life is much
	 * clearer if we subtract 1 from ordinal first -- then the values
	 * of ordinal at 400-year boundaries are exactly those divisible
	 * by DI400Y:
	 *
	 *    D  M   Y            n              n-1
	 *    -- --- ----        ----------     ----------------
	 *    31 Dec -400        -DI400Y       -DI400Y -1
	 *     1 Jan -399         -DI400Y +1   -DI400Y      400-year boundary
	 *    ...
	 *    30 Dec  000        -1             -2
	 *    31 Dec  000         0             -1
	 *     1 Jan  001         1              0          400-year boundary
	 *     2 Jan  001         2              1
	 *     3 Jan  001         3              2
	 *    ...
	 *    31 Dec  400         DI400Y        DI400Y -1
	 *     1 Jan  401         DI400Y +1     DI400Y      400-year boundary
	 */
	assert(ordinal >= 1);
	--ordinal;
	n400 = ordinal / DI400Y;
	n = ordinal % DI400Y;
	*year = n400 * 400 + 1;

	/* Now n is the (non-negative) offset, in days, from January 1 of
	 * year, to the desired date.  Now compute how many 100-year cycles
	 * precede n.
	 * Note that it's possible for n100 to equal 4!  In that case 4 full
	 * 100-year cycles precede the desired day, which implies the
	 * desired day is December 31 at the end of a 400-year cycle.
	 */
	n100 = n / DI100Y;
	n = n % DI100Y;

	/* Now compute how many 4-year cycles precede it. */
	n4 = n / DI4Y;
	n = n % DI4Y;

	/* And now how many single years.  Again n1 can be 4, and again
	 * meaning that the desired day is December 31 at the end of the
	 * 4-year cycle.
	 */
	n1 = n / 365;
	n = n % 365;

	*year += n100 * 100 + n4 * 4 + n1;
	if (n1 == 4 || n100 == 4) {
		assert(n == 0);
		*year -= 1;
		*month = 12;
		*day = 31;
		return;
	}

	/* Now the year is correct, and n is the offset from January 1.  We
	 * find the month via an estimate that's either exact or one too
	 * large.
	 */
	leapyear = n1 == 3 && (n4 != 24 || n100 == 3);
	assert(leapyear == is_leap(*year));
	*month = (n + 50) >> 5;
	preceding = (_days_before_month[*month] + (*month > 2 && leapyear));
	if (preceding > n) {
		/* estimate is too large */
		*month -= 1;
		preceding -= days_in_month(*year, *month);
	}
	n -= preceding;
	assert(0 <= n);
	assert(n < days_in_month(*year, *month));

	*day = n + 1;
}

/* year, month, day -> ordinal, considering 01-Jan-0001 as day 1. */
static int
ymd_to_ord(int year, int month, int day)
{
	return days_before_year(year) + days_before_month(year, month) + day;
}

/* Day of week, where Monday==0, ..., Sunday==6.  1/1/1 was a Monday. */
static int
weekday(int year, int month, int day)
{
	return (ymd_to_ord(year, month, day) + 6) % 7;
}

/* Ordinal of the Monday starting week 1 of the ISO year.  Week 1 is the
 * first calendar week containing a Thursday.
 */
static int
iso_week1_monday(int year)
{
	int first_day = ymd_to_ord(year, 1, 1);	/* ord of 1/1 */
	/* 0 if 1/1 is a Monday, 1 if a Tue, etc. */
	int first_weekday = (first_day + 6) % 7;
	/* ordinal of closest Monday at or before 1/1 */
	int week1_monday  = first_day - first_weekday;

	if (first_weekday > 3)	/* if 1/1 was Fri, Sat, Sun */
		week1_monday += 7;
	return week1_monday;
}

/* ---------------------------------------------------------------------------
 * Range checkers.
 */

/* Check that -MAX_DELTA_DAYS <= days <= MAX_DELTA_DAYS.  If so, return 0.
 * If not, raise OverflowError and return -1.
 */
static int
check_delta_day_range(int days)
{
	if (-MAX_DELTA_DAYS <= days && days <= MAX_DELTA_DAYS)
		return 0;
	PyErr_Format(PyExc_OverflowError,
		     "days=%d; must have magnitude <= %d",
		     days, MAX_DELTA_DAYS);
	return -1;
}

/* Check that date arguments are in range.  Return 0 if they are.  If they
 * aren't, raise ValueError and return -1.
 */
static int
check_date_args(int year, int month, int day)
{

	if (year < MINYEAR || year > MAXYEAR) {
		PyErr_SetString(PyExc_ValueError,
				"year is out of range");
		return -1;
	}
	if (month < 1 || month > 12) {
		PyErr_SetString(PyExc_ValueError,
				"month must be in 1..12");
		return -1;
	}
	if (day < 1 || day > days_in_month(year, month)) {
		PyErr_SetString(PyExc_ValueError,
				"day is out of range for month");
		return -1;
	}
	return 0;
}

/* Check that time arguments are in range.  Return 0 if they are.  If they
 * aren't, raise ValueError and return -1.
 */
static int
check_time_args(int h, int m, int s, int us)
{
	if (h < 0 || h > 23) {
		PyErr_SetString(PyExc_ValueError,
				"hour must be in 0..23");
		return -1;
	}
	if (m < 0 || m > 59) {
		PyErr_SetString(PyExc_ValueError,
				"minute must be in 0..59");
		return -1;
	}
	if (s < 0 || s > 59) {
		PyErr_SetString(PyExc_ValueError,
				"second must be in 0..59");
		return -1;
	}
	if (us < 0 || us > 999999) {
		PyErr_SetString(PyExc_ValueError,
				"microsecond must be in 0..999999");
		return -1;
	}
	return 0;
}

/* ---------------------------------------------------------------------------
 * Normalization utilities.
 */

/* One step of a mixed-radix conversion.  A "hi" unit is equivalent to
 * factor "lo" units.  factor must be > 0.  If *lo is less than 0, or
 * at least factor, enough of *lo is converted into "hi" units so that
 * 0 <= *lo < factor.  The input values must be such that int overflow
 * is impossible.
 */
static void
normalize_pair(int *hi, int *lo, int factor)
{
	assert(factor > 0);
	assert(lo != hi);
	if (*lo < 0 || *lo >= factor) {
		const int num_hi = divmod(*lo, factor, lo);
		const int new_hi = *hi + num_hi;
		assert(! SIGNED_ADD_OVERFLOWED(new_hi, *hi, num_hi));
		*hi = new_hi;
	}
	assert(0 <= *lo && *lo < factor);
}

/* Fiddle days (d), seconds (s), and microseconds (us) so that
 * 	0 <= *s < 24*3600
 * 	0 <= *us < 1000000
 * The input values must be such that the internals don't overflow.
 * The way this routine is used, we don't get close.
 */
static void
normalize_d_s_us(int *d, int *s, int *us)
{
	if (*us < 0 || *us >= 1000000) {
		normalize_pair(s, us, 1000000);
		/* |s| can't be bigger than about
		 * |original s| + |original us|/1000000 now.
		 */

	}
	if (*s < 0 || *s >= 24*3600) {
		normalize_pair(d, s, 24*3600);
		/* |d| can't be bigger than about
		 * |original d| +
		 * (|original s| + |original us|/1000000) / (24*3600) now.
		 */
	}
	assert(0 <= *s && *s < 24*3600);
	assert(0 <= *us && *us < 1000000);
}

/* Fiddle years (y), months (m), and days (d) so that
 * 	1 <= *m <= 12
 * 	1 <= *d <= days_in_month(*y, *m)
 * The input values must be such that the internals don't overflow.
 * The way this routine is used, we don't get close.
 */
static void
normalize_y_m_d(int *y, int *m, int *d)
{
	int dim;	/* # of days in month */

	/* This gets muddy:  the proper range for day can't be determined
	 * without knowing the correct month and year, but if day is, e.g.,
	 * plus or minus a million, the current month and year values make
	 * no sense (and may also be out of bounds themselves).
	 * Saying 12 months == 1 year should be non-controversial.
	 */
	if (*m < 1 || *m > 12) {
		--*m;
		normalize_pair(y, m, 12);
		++*m;
		/* |y| can't be bigger than about
		 * |original y| + |original m|/12 now.
		 */
	}
	assert(1 <= *m && *m <= 12);

	/* Now only day can be out of bounds (year may also be out of bounds
	 * for a datetime object, but we don't care about that here).
	 * If day is out of bounds, what to do is arguable, but at least the
	 * method here is principled and explainable.
	 */
	dim = days_in_month(*y, *m);
	if (*d < 1 || *d > dim) {
		/* Move day-1 days from the first of the month.  First try to
		 * get off cheap if we're only one day out of range
		 * (adjustments for timezone alone can't be worse than that).
		 */
		if (*d == 0) {
			--*m;
			if (*m > 0)
				*d = days_in_month(*y, *m);
			else {
				--*y;
				*m = 12;
				*d = 31;
			}
		}
		else if (*d == dim + 1) {
			/* move forward a day */
			++*m;
			*d = 1;
			if (*m > 12) {
				*m = 1;
				++*y;
			}
		}
		else {
			int ordinal = ymd_to_ord(*y, *m, 1) +
						  *d - 1;
			ord_to_ymd(ordinal, y, m, d);
		}
	}
	assert(*m > 0);
	assert(*d > 0);
}

/* Fiddle out-of-bounds months and days so that the result makes some kind
 * of sense.  The parameters are both inputs and outputs.  Returns < 0 on
 * failure, where failure means the adjusted year is out of bounds.
 */
static int
normalize_date(int *year, int *month, int *day)
{
	int result;

	normalize_y_m_d(year, month, day);
	if (MINYEAR <= *year && *year <= MAXYEAR)
		result = 0;
	else {
		PyErr_SetString(PyExc_OverflowError,
				"date value out of range");
		result = -1;
	}
	return result;
}

/* Force all the datetime fields into range.  The parameters are both
 * inputs and outputs.  Returns < 0 on error.
 */
static int
normalize_datetime(int *year, int *month, int *day,
                   int *hour, int *minute, int *second,
                   int *microsecond)
{
	normalize_pair(second, microsecond, 1000000);
	normalize_pair(minute, second, 60);
	normalize_pair(hour, minute, 60);
	normalize_pair(day, hour, 24);
	return normalize_date(year, month, day);
}

/* ---------------------------------------------------------------------------
 * tzinfo helpers.
 */

/* Ensure that p is None or of a tzinfo subclass.  Return 0 if OK; if not
 * raise TypeError and return -1.
 */
static int
check_tzinfo_subclass(PyObject *p)
{
	if (p == Py_None || PyTZInfo_Check(p))
		return 0;
	PyErr_Format(PyExc_TypeError,
		     "tzinfo argument must be None or of a tzinfo subclass, "
		     "not type '%s'",
		     p->ob_type->tp_name);
	return -1;
}

/* Return tzinfo.methname(self), without any checking of results.
 * If tzinfo is None, returns None.
 */
static PyObject *
call_tzinfo_method(PyObject *self, PyObject *tzinfo, char *methname)
{
	PyObject *result;

	assert(self && tzinfo && methname);
	assert(check_tzinfo_subclass(tzinfo) >= 0);
	if (tzinfo == Py_None) {
		result = Py_None;
		Py_INCREF(result);
	}
	else
		result = PyObject_CallMethod(tzinfo, methname, "O", self);
	return result;
}

/* If self has a tzinfo member, return a BORROWED reference to it.  Else
 * return NULL, which is NOT AN ERROR.  There are no error returns here,
 * and the caller must not decref the result.
 */
static PyObject *
get_tzinfo_member(PyObject *self)
{
	PyObject *tzinfo = NULL;

	if (PyDateTimeTZ_Check(self))
		tzinfo = ((PyDateTime_DateTimeTZ *)self)->tzinfo;
	else if (PyTimeTZ_Check(self))
		tzinfo = ((PyDateTime_TimeTZ *)self)->tzinfo;

	return tzinfo;
}

/* Internal helper.
 * Call getattr(tzinfo, name)(tzinfoarg), and extract an int from the
 * result.  tzinfo must be an instance of the tzinfo class.  If the method
 * returns None, this returns 0 and sets *none to 1.  If the method doesn't
 * return a Python int or long or timedelta, TypeError is raised and this
 * returns -1.  If it returns an int or long, but is outside the valid
 * range for a UTC minute offset, or it returns a timedelta and the value is
 * out of range or isn't a whole number of minutes, ValueError is raised and
 * this returns -1.
 * Else *none is set to 0 and the integer method result is returned.
 */
static int
call_utc_tzinfo_method(PyObject *tzinfo, char *name, PyObject *tzinfoarg,
		       int *none)
{
	PyObject *u;
	long result = -1;	/* Py{Int,Long}_AsLong return long */

	assert(tzinfo != NULL);
	assert(PyTZInfo_Check(tzinfo));
	assert(tzinfoarg != NULL);

	*none = 0;
	u = call_tzinfo_method(tzinfoarg, tzinfo, name);
	if (u == NULL)
		return -1;

	else if (u == Py_None) {
		result = 0;
		*none = 1;
	}
	else if (PyInt_Check(u))
		result = PyInt_AS_LONG(u);

	else if (PyLong_Check(u))
		result = PyLong_AsLong(u);

	else if (PyDelta_Check(u)) {
		const int days = GET_TD_DAYS(u);
		if (days < -1 || days > 0)
			result = 24*60;	/* trigger ValueError below */
		else {
			/* next line can't overflow because we know days
			 * is -1 or 0 now
			 */
			int ss = days * 24 * 3600 + GET_TD_SECONDS(u);
			result = divmod(ss, 60, &ss);
			if (ss || GET_TD_MICROSECONDS(u)) {
				PyErr_Format(PyExc_ValueError,
					     "tzinfo.%s() must return a "
					     "whole number of minutes",
					     name);
				result = -1;
			}
		}
	}
	else {
		PyErr_Format(PyExc_TypeError,
			     "tzinfo.%s() must return None, integer or "
			     "timedelta, not '%s'",
			     name, u->ob_type->tp_name);
	}

	Py_DECREF(u);
	if (result < -1439 || result > 1439) {
		PyErr_Format(PyExc_ValueError,
			     "tzinfo.%s() returned %ld; must be in "
			     "-1439 .. 1439",
			     name, result);
		result = -1;
	}
	return (int)result;
}

/* Call tzinfo.utcoffset(tzinfoarg), and extract an integer from the
 * result.  tzinfo must be an instance of the tzinfo class.  If utcoffset()
 * returns None, call_utcoffset returns 0 and sets *none to 1.  If uctoffset()
 & doesn't return a Python int or long, TypeError is raised and this
 * returns -1.  If utcoffset() returns an int outside the legitimate range
 * for a UTC offset, ValueError is raised and this returns -1.  Else
 * *none is set to 0 and the offset is returned.
 */
static int
call_utcoffset(PyObject *tzinfo, PyObject *tzinfoarg, int *none)
{
	return call_utc_tzinfo_method(tzinfo, "utcoffset", tzinfoarg, none);
}

static PyObject *new_delta(int d, int sec, int usec, int normalize);

/* Call tzinfo.name(self) and return the offset as a timedelta or None. */
static PyObject *
offset_as_timedelta(PyObject *self, PyObject *tzinfo, char *name) {
	PyObject *result;

	if (tzinfo == Py_None) {
		result = Py_None;
		Py_INCREF(result);
	}
	else {
		int none;
		int offset = call_utc_tzinfo_method(tzinfo, name, self, &none);
		if (offset < 0 && PyErr_Occurred())
			return NULL;
		if (none) {
			result = Py_None;
			Py_INCREF(result);
		}
		else
			result = new_delta(0, offset * 60, 0, 1);
	}
	return result;
}

/* Call tzinfo.dst(tzinfoarg), and extract an integer from the
 * result.  tzinfo must be an instance of the tzinfo class.  If dst()
 * returns None, call_dst returns 0 and sets *none to 1.  If dst()
 & doesn't return a Python int or long, TypeError is raised and this
 * returns -1.  If dst() returns an int outside the legitimate range
 * for a UTC offset, ValueError is raised and this returns -1.  Else
 * *none is set to 0 and the offset is returned.
 */
static int
call_dst(PyObject *tzinfo, PyObject *tzinfoarg, int *none)
{
	return call_utc_tzinfo_method(tzinfo, "dst", tzinfoarg, none);
}

/* Call tzinfo.tzname(self), and return the result.  tzinfo must be
 * an instance of the tzinfo class or None.  If tzinfo isn't None, and
 * tzname() doesn't return None ora string, TypeError is raised and this
 * returns NULL.
 */
static PyObject *
call_tzname(PyObject *self, PyObject *tzinfo)
{
	PyObject *result;

	assert(self != NULL);
	assert(tzinfo != NULL);
	assert(check_tzinfo_subclass(tzinfo) >= 0);

	if (tzinfo == Py_None) {
		result = Py_None;
		Py_INCREF(result);
	}
	else
		result = PyObject_CallMethod(tzinfo, "tzname", "O", self);

	if (result != NULL && result != Py_None && ! PyString_Check(result)) {
		PyErr_Format(PyExc_TypeError, "tzinfo.tzname() must "
			     "return None or a string, not '%s'",
			     result->ob_type->tp_name);
		Py_DECREF(result);
		result = NULL;
	}
	return result;
}

typedef enum {
	      /* an exception has been set; the caller should pass it on */
	      OFFSET_ERROR,

	      /* type isn't date, datetime, datetimetz subclass, time, or
	       * timetz subclass
	       */
	      OFFSET_UNKNOWN,

	      /* date,
	       * datetime,
	       * datetimetz with None tzinfo,
	       * datetimetz where utcoffset() returns None
	       * time,
	       * timetz with None tzinfo,
	       * timetz where utcoffset() returns None
	       */
	      OFFSET_NAIVE,

	      /* timetz where utcoffset() doesn't return None,
	       * datetimetz where utcoffset() doesn't return None
	       */
	      OFFSET_AWARE,
} naivety;

/* Classify an object as to whether it's naive or offset-aware.  See
 * the "naivety" typedef for details.  If the type is aware, *offset is set
 * to minutes east of UTC (as returned by the tzinfo.utcoffset() method).
 * If the type is offset-naive (or unknown, or error), *offset is set to 0.
 */
static naivety
classify_utcoffset(PyObject *op, int *offset)
{
	int none;
	PyObject *tzinfo;

	*offset = 0;
	tzinfo = get_tzinfo_member(op);	/* NULL means no tzinfo, not error */
	if (tzinfo == Py_None)
		return OFFSET_NAIVE;
	if (tzinfo == NULL) {
		/* note that a datetime passes the PyDate_Check test */
		return (PyTime_Check(op) || PyDate_Check(op)) ?
		       OFFSET_NAIVE : OFFSET_UNKNOWN;
	}
	*offset = call_utcoffset(tzinfo, op, &none);
	if (*offset == -1 && PyErr_Occurred())
		return OFFSET_ERROR;
	return none ? OFFSET_NAIVE : OFFSET_AWARE;
}

/* repr is like "someclass(arg1, arg2)".  If tzinfo isn't None,
 * stuff
 *     ", tzinfo=" + repr(tzinfo)
 * before the closing ")".
 */
static PyObject *
append_keyword_tzinfo(PyObject *repr, PyObject *tzinfo)
{
	PyObject *temp;

	assert(PyString_Check(repr));
	assert(tzinfo);
	if (tzinfo == Py_None)
		return repr;
	/* Get rid of the trailing ')'. */
	assert(PyString_AsString(repr)[PyString_Size(repr)-1] == ')');
	temp = PyString_FromStringAndSize(PyString_AsString(repr),
					  PyString_Size(repr) - 1);
	Py_DECREF(repr);
	if (temp == NULL)
		return NULL;
	repr = temp;

	/* Append ", tzinfo=". */
	PyString_ConcatAndDel(&repr, PyString_FromString(", tzinfo="));

	/* Append repr(tzinfo). */
	PyString_ConcatAndDel(&repr, PyObject_Repr(tzinfo));

	/* Add a closing paren. */
	PyString_ConcatAndDel(&repr, PyString_FromString(")"));
	return repr;
}

/* ---------------------------------------------------------------------------
 * String format helpers.
 */

static PyObject *
format_ctime(PyDateTime_Date *date,
             int hours, int minutes, int seconds)
{
	static char *DayNames[] = {
		"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"
	};
	static char *MonthNames[] = {
		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
	};

	char buffer[128];
	int wday = weekday(GET_YEAR(date), GET_MONTH(date), GET_DAY(date));

	PyOS_snprintf(buffer, sizeof(buffer), "%s %s %2d %02d:%02d:%02d %04d",
		      DayNames[wday], MonthNames[GET_MONTH(date) - 1],
		      GET_DAY(date), hours, minutes, seconds,
		      GET_YEAR(date));
	return PyString_FromString(buffer);
}

/* Add an hours & minutes UTC offset string to buf.  buf has no more than
 * buflen bytes remaining.  The UTC offset is gotten by calling
 * tzinfo.uctoffset(tzinfoarg).  If that returns None, \0 is stored into
 * *buf, and that's all.  Else the returned value is checked for sanity (an
 * integer in range), and if that's OK it's converted to an hours & minutes
 * string of the form
 *   sign HH sep MM
 * Returns 0 if everything is OK.  If the return value from utcoffset() is
 * bogus, an appropriate exception is set and -1 is returned.
 */
static int
format_utcoffset(char *buf, size_t buflen, const char *sep,
		PyObject *tzinfo, PyObject *tzinfoarg)
{
	int offset;
	int hours;
	int minutes;
	char sign;
	int none;

	offset = call_utcoffset(tzinfo, tzinfoarg, &none);
	if (offset == -1 && PyErr_Occurred())
		return -1;
	if (none) {
		*buf = '\0';
		return 0;
	}
	sign = '+';
	if (offset < 0) {
		sign = '-';
		offset = - offset;
	}
	hours = divmod(offset, 60, &minutes);
	PyOS_snprintf(buf, buflen, "%c%02d%s%02d", sign, hours, sep, minutes);
	return 0;
}

/* I sure don't want to reproduce the strftime code from the time module,
 * so this imports the module and calls it.  All the hair is due to
 * giving special meanings to the %z and %Z format codes via a preprocessing
 * step on the format string.
 */
static PyObject *
wrap_strftime(PyObject *object, PyObject *format, PyObject *timetuple)
{
	PyObject *result = NULL;	/* guilty until proved innocent */

	PyObject *zreplacement = NULL;	/* py string, replacement for %z */
	PyObject *Zreplacement = NULL;	/* py string, replacement for %Z */

	char *pin;	/* pointer to next char in input format */
	char ch;	/* next char in input format */

	PyObject *newfmt = NULL;	/* py string, the output format */
	char *pnew;	/* pointer to available byte in output format */
	char totalnew;	/* number bytes total in output format buffer,
			   exclusive of trailing \0 */
	char usednew;	/* number bytes used so far in output format buffer */

	char *ptoappend; /* pointer to string to append to output buffer */
	int ntoappend;	/* # of bytes to append to output buffer */

	assert(object && format && timetuple);
	assert(PyString_Check(format));

	/* Give up if the year is before 1900.
	 * Python strftime() plays games with the year, and different
	 * games depending on whether envar PYTHON2K is set.  This makes
	 * years before 1900 a nightmare, even if the platform strftime
	 * supports them (and not all do).
	 * We could get a lot farther here by avoiding Python's strftime
	 * wrapper and calling the C strftime() directly, but that isn't
	 * an option in the Python implementation of this module.
	 */
	{
		long year;
		PyObject *pyyear = PySequence_GetItem(timetuple, 0);
		if (pyyear == NULL) return NULL;
		assert(PyInt_Check(pyyear));
		year = PyInt_AsLong(pyyear);
		Py_DECREF(pyyear);
		if (year < 1900) {
			PyErr_Format(PyExc_ValueError, "year=%ld is before "
				     "1900; the datetime strftime() "
	                             "methods require year >= 1900",
	                             year);
	                return NULL;
		}
	}

	/* Scan the input format, looking for %z and %Z escapes, building
	 * a new format.  Since computing the replacements for those codes
	 * is expensive, don't unless they're actually used.
	 */
	totalnew = PyString_Size(format);	/* realistic if no %z/%Z */
	newfmt = PyString_FromStringAndSize(NULL, totalnew);
	if (newfmt == NULL) goto Done;
	pnew = PyString_AsString(newfmt);
	usednew = 0;

	pin = PyString_AsString(format);
	while ((ch = *pin++) != '\0') {
		if (ch != '%') {
			ptoappend = pin - 1;
			ntoappend = 1;
		}
		else if ((ch = *pin++) == '\0') {
			/* There's a lone trailing %; doesn't make sense. */
			PyErr_SetString(PyExc_ValueError, "strftime format "
					"ends with raw %");
			goto Done;
		}
		/* A % has been seen and ch is the character after it. */
		else if (ch == 'z') {
			if (zreplacement == NULL) {
				/* format utcoffset */
				char buf[100];
				PyObject *tzinfo = get_tzinfo_member(object);
				zreplacement = PyString_FromString("");
				if (zreplacement == NULL) goto Done;
				if (tzinfo != Py_None && tzinfo != NULL) {
					if (format_utcoffset(buf,
							     sizeof(buf),
							     "",
							     tzinfo,
							     object) < 0)
						goto Done;
					Py_DECREF(zreplacement);
					zreplacement = PyString_FromString(buf);
					if (zreplacement == NULL) goto Done;
				}
			}
			assert(zreplacement != NULL);
			ptoappend = PyString_AsString(zreplacement);
			ntoappend = PyString_Size(zreplacement);
		}
		else if (ch == 'Z') {
			/* format tzname */
			if (Zreplacement == NULL) {
				PyObject *tzinfo = get_tzinfo_member(object);
				Zreplacement = PyString_FromString("");
				if (Zreplacement == NULL) goto Done;
				if (tzinfo != Py_None && tzinfo != NULL) {
					PyObject *temp = call_tzname(object,
								     tzinfo);
					if (temp == NULL) goto Done;
					if (temp != Py_None) {
						assert(PyString_Check(temp));
						/* Since the tzname is getting
						 * stuffed into the format, we
						 * have to double any % signs
						 * so that strftime doesn't
						 * treat them as format codes.
						 */
						Py_DECREF(Zreplacement);
						Zreplacement = PyObject_CallMethod(
							temp, "replace",
							"ss", "%", "%%");
						Py_DECREF(temp);
						if (Zreplacement == NULL)
							goto Done;
					}
					else
						Py_DECREF(temp);
				}
			}
			assert(Zreplacement != NULL);
			ptoappend = PyString_AsString(Zreplacement);
			ntoappend = PyString_Size(Zreplacement);
		}
		else {
			/* percent followed by neither z nor Z */
			ptoappend = pin - 2;
			ntoappend = 2;
		}

 		/* Append the ntoappend chars starting at ptoappend to
 		 * the new format.
 		 */
 		assert(ntoappend >= 0);
 		if (ntoappend == 0)
 			continue;
 		while (usednew + ntoappend > totalnew) {
 			int bigger = totalnew << 1;
 			if ((bigger >> 1) != totalnew) { /* overflow */
 				PyErr_NoMemory();
 				goto Done;
 			}
 			if (_PyString_Resize(&newfmt, bigger) < 0)
 				goto Done;
 			totalnew = bigger;
 			pnew = PyString_AsString(newfmt) + usednew;
 		}
		memcpy(pnew, ptoappend, ntoappend);
		pnew += ntoappend;
		usednew += ntoappend;
		assert(usednew <= totalnew);
	}  /* end while() */

	if (_PyString_Resize(&newfmt, usednew) < 0)
		goto Done;
	{
		PyObject *time = PyImport_ImportModule("time");
		if (time == NULL)
			goto Done;
		result = PyObject_CallMethod(time, "strftime", "OO",
					     newfmt, timetuple);
		Py_DECREF(time);
    	}
 Done:
	Py_XDECREF(zreplacement);
	Py_XDECREF(Zreplacement);
	Py_XDECREF(newfmt);
    	return result;
}

static char *
isoformat_date(PyDateTime_Date *dt, char buffer[], int bufflen)
{
	int x;
	x = PyOS_snprintf(buffer, bufflen,
			  "%04d-%02d-%02d",
			  GET_YEAR(dt), GET_MONTH(dt), GET_DAY(dt));
	return buffer + x;
}

static void
isoformat_time(PyDateTime_DateTime *dt, char buffer[], int bufflen)
{
	int us = DATE_GET_MICROSECOND(dt);

	PyOS_snprintf(buffer, bufflen,
		      "%02d:%02d:%02d",	/* 8 characters */
		      DATE_GET_HOUR(dt),
		      DATE_GET_MINUTE(dt),
		      DATE_GET_SECOND(dt));
	if (us)
		PyOS_snprintf(buffer + 8, bufflen - 8, ".%06d", us);
}

/* ---------------------------------------------------------------------------
 * Wrap functions from the time module.  These aren't directly available
 * from C.  Perhaps they should be.
 */

/* Call time.time() and return its result (a Python float). */
static PyObject *
time_time(void)
{
	PyObject *result = NULL;
	PyObject *time = PyImport_ImportModule("time");

	if (time != NULL) {
		result = PyObject_CallMethod(time, "time", "()");
		Py_DECREF(time);
	}
	return result;
}

/* Build a time.struct_time.  The weekday and day number are automatically
 * computed from the y,m,d args.
 */
static PyObject *
build_struct_time(int y, int m, int d, int hh, int mm, int ss, int dstflag)
{
	PyObject *time;
	PyObject *result = NULL;

	time = PyImport_ImportModule("time");
	if (time != NULL) {
		result = PyObject_CallMethod(time, "struct_time",
					     "((iiiiiiiii))",
					     y, m, d,
					     hh, mm, ss,
				 	     weekday(y, m, d),
				 	     days_before_month(y, m) + d,
				 	     dstflag);
		Py_DECREF(time);
	}
	return result;
}

/* ---------------------------------------------------------------------------
 * Miscellaneous helpers.
 */

/* For obscure reasons, we need to use tp_richcompare instead of tp_compare.
 * The comparisons here all most naturally compute a cmp()-like result.
 * This little helper turns that into a bool result for rich comparisons.
 */
static PyObject *
diff_to_bool(int diff, int op)
{
	PyObject *result;
	int istrue;

	switch (op) {
		case Py_EQ: istrue = diff == 0; break;
		case Py_NE: istrue = diff != 0; break;
		case Py_LE: istrue = diff <= 0; break;
		case Py_GE: istrue = diff >= 0; break;
		case Py_LT: istrue = diff < 0; break;
		case Py_GT: istrue = diff > 0; break;
		default:
			assert(! "op unknown");
			istrue = 0; /* To shut up compiler */
	}
	result = istrue ? Py_True : Py_False;
	Py_INCREF(result);
	return result;
}

/* ---------------------------------------------------------------------------
 * Helpers for setting object fields.  These work on pointers to the
 * appropriate base class.
 */

/* For date, datetime and datetimetz. */
static void
set_date_fields(PyDateTime_Date *self, int y, int m, int d)
{
	self->hashcode = -1;
	SET_YEAR(self, y);
	SET_MONTH(self, m);
	SET_DAY(self, d);
}

/* For datetime and datetimetz. */
static void
set_datetime_time_fields(PyDateTime_Date *self, int h, int m, int s, int us)
{
	DATE_SET_HOUR(self, h);
	DATE_SET_MINUTE(self, m);
	DATE_SET_SECOND(self, s);
	DATE_SET_MICROSECOND(self, us);
}

/* For time and timetz. */
static void
set_time_fields(PyDateTime_Time *self, int h, int m, int s, int us)
{
	self->hashcode = -1;
	TIME_SET_HOUR(self, h);
	TIME_SET_MINUTE(self, m);
	TIME_SET_SECOND(self, s);
	TIME_SET_MICROSECOND(self, us);
}

/* ---------------------------------------------------------------------------
 * Create various objects, mostly without range checking.
 */

/* Create a date instance with no range checking. */
static PyObject *
new_date(int year, int month, int day)
{
	PyDateTime_Date *self;

	self = PyObject_New(PyDateTime_Date, &PyDateTime_DateType);
	if (self != NULL)
		set_date_fields(self, year, month, day);
	return (PyObject *) self;
}

/* Create a datetime instance with no range checking. */
static PyObject *
new_datetime(int year, int month, int day, int hour, int minute,
             int second, int usecond)
{
	PyDateTime_DateTime *self;

	self = PyObject_New(PyDateTime_DateTime, &PyDateTime_DateTimeType);
	if (self != NULL) {
		set_date_fields((PyDateTime_Date *)self, year, month, day);
		set_datetime_time_fields((PyDateTime_Date *)self,
					 hour, minute, second, usecond);
	}
	return (PyObject *) self;
}

/* Create a datetimetz instance with no range checking. */
static PyObject *
new_datetimetz(int year, int month, int day, int hour, int minute,
	       int second, int usecond, PyObject *tzinfo)
{
	PyDateTime_DateTimeTZ *self;

	self = PyObject_New(PyDateTime_DateTimeTZ, &PyDateTime_DateTimeTZType);
	if (self != NULL) {
		set_date_fields((PyDateTime_Date *)self, year, month, day);
		set_datetime_time_fields((PyDateTime_Date *)self,
					 hour, minute, second, usecond);
		Py_INCREF(tzinfo);
		self->tzinfo = tzinfo;
	}
	return (PyObject *) self;
}

/* Create a time instance with no range checking. */
static PyObject *
new_time(int hour, int minute, int second, int usecond)
{
	PyDateTime_Time *self;

	self = PyObject_New(PyDateTime_Time, &PyDateTime_TimeType);
	if (self != NULL)
		set_time_fields(self, hour, minute, second, usecond);
	return (PyObject *) self;
}

/* Create a timetz instance with no range checking. */
static PyObject *
new_timetz(int hour, int minute, int second, int usecond, PyObject *tzinfo)
{
	PyDateTime_TimeTZ *self;

	self = PyObject_New(PyDateTime_TimeTZ, &PyDateTime_TimeTZType);
	if (self != NULL) {
		set_time_fields((PyDateTime_Time *)self,
				hour, minute, second, usecond);
		Py_INCREF(tzinfo);
		self->tzinfo = tzinfo;
	}
	return (PyObject *) self;
}

/* Create a timedelta instance.  Normalize the members iff normalize is
 * true.  Passing false is a speed optimization, if you know for sure
 * that seconds and microseconds are already in their proper ranges.  In any
 * case, raises OverflowError and returns NULL if the normalized days is out
 * of range).
 */
static PyObject *
new_delta(int days, int seconds, int microseconds, int normalize)
{
	PyDateTime_Delta *self;

	if (normalize)
		normalize_d_s_us(&days, &seconds, &microseconds);
	assert(0 <= seconds && seconds < 24*3600);
	assert(0 <= microseconds && microseconds < 1000000);

 	if (check_delta_day_range(days) < 0)
 		return NULL;

	self = PyObject_New(PyDateTime_Delta, &PyDateTime_DeltaType);
	if (self != NULL) {
		self->hashcode = -1;
		SET_TD_DAYS(self, days);
		SET_TD_SECONDS(self, seconds);
		SET_TD_MICROSECONDS(self, microseconds);
	}
	return (PyObject *) self;
}


/* ---------------------------------------------------------------------------
 * Cached Python objects; these are set by the module init function.
 */

/* Conversion factors. */
static PyObject *us_per_us = NULL;	/* 1 */
static PyObject *us_per_ms = NULL;	/* 1000 */
static PyObject *us_per_second = NULL;	/* 1000000 */
static PyObject *us_per_minute = NULL;	/* 1e6 * 60 as Python int */
static PyObject *us_per_hour = NULL;	/* 1e6 * 3600 as Python long */
static PyObject *us_per_day = NULL;	/* 1e6 * 3600 * 24 as Python long */
static PyObject *us_per_week = NULL;	/* 1e6*3600*24*7 as Python long */
static PyObject *seconds_per_day = NULL; /* 3600*24 as Python int */

/* Callables to support unpickling. */
static PyObject *date_unpickler_object = NULL;
static PyObject *datetime_unpickler_object = NULL;
static PyObject *datetimetz_unpickler_object = NULL;
static PyObject *tzinfo_unpickler_object = NULL;
static PyObject *time_unpickler_object = NULL;
static PyObject *timetz_unpickler_object = NULL;

/* ---------------------------------------------------------------------------
 * Class implementations.
 */

/*
 * PyDateTime_Delta implementation.
 */

/* Convert a timedelta to a number of us,
 * 	(24*3600*self.days + self.seconds)*1000000 + self.microseconds
 * as a Python int or long.
 * Doing mixed-radix arithmetic by hand instead is excruciating in C,
 * due to ubiquitous overflow possibilities.
 */
static PyObject *
delta_to_microseconds(PyDateTime_Delta *self)
{
	PyObject *x1 = NULL;
	PyObject *x2 = NULL;
	PyObject *x3 = NULL;
	PyObject *result = NULL;

	x1 = PyInt_FromLong(GET_TD_DAYS(self));
	if (x1 == NULL)
		goto Done;
	x2 = PyNumber_Multiply(x1, seconds_per_day);	/* days in seconds */
	if (x2 == NULL)
		goto Done;
	Py_DECREF(x1);
	x1 = NULL;

	/* x2 has days in seconds */
	x1 = PyInt_FromLong(GET_TD_SECONDS(self));	/* seconds */
	if (x1 == NULL)
		goto Done;
	x3 = PyNumber_Add(x1, x2);	/* days and seconds in seconds */
	if (x3 == NULL)
		goto Done;
	Py_DECREF(x1);
	Py_DECREF(x2);
	x1 = x2 = NULL;

	/* x3 has days+seconds in seconds */
	x1 = PyNumber_Multiply(x3, us_per_second);	/* us */
	if (x1 == NULL)
		goto Done;
	Py_DECREF(x3);
	x3 = NULL;

	/* x1 has days+seconds in us */
	x2 = PyInt_FromLong(GET_TD_MICROSECONDS(self));
	if (x2 == NULL)
		goto Done;
	result = PyNumber_Add(x1, x2);

Done:
	Py_XDECREF(x1);
	Py_XDECREF(x2);
	Py_XDECREF(x3);
	return result;
}

/* Convert a number of us (as a Python int or long) to a timedelta.
 */
static PyObject *
microseconds_to_delta(PyObject *pyus)
{
	int us;
	int s;
	int d;
	long temp;

	PyObject *tuple = NULL;
	PyObject *num = NULL;
	PyObject *result = NULL;

	tuple = PyNumber_Divmod(pyus, us_per_second);
	if (tuple == NULL)
		goto Done;

	num = PyTuple_GetItem(tuple, 1);	/* us */
	if (num == NULL)
		goto Done;
	temp = PyLong_AsLong(num);
	num = NULL;
	if (temp == -1 && PyErr_Occurred())
		goto Done;
	assert(0 <= temp && temp < 1000000);
	us = (int)temp;
	if (us < 0) {
		/* The divisor was positive, so this must be an error. */
		assert(PyErr_Occurred());
		goto Done;
	}

	num = PyTuple_GetItem(tuple, 0);	/* leftover seconds */
	if (num == NULL)
		goto Done;
	Py_INCREF(num);
	Py_DECREF(tuple);

	tuple = PyNumber_Divmod(num, seconds_per_day);
	if (tuple == NULL)
		goto Done;
	Py_DECREF(num);

	num = PyTuple_GetItem(tuple, 1); 	/* seconds */
	if (num == NULL)
		goto Done;
	temp = PyLong_AsLong(num);
	num = NULL;
	if (temp == -1 && PyErr_Occurred())
		goto Done;
	assert(0 <= temp && temp < 24*3600);
	s = (int)temp;

	if (s < 0) {
		/* The divisor was positive, so this must be an error. */
		assert(PyErr_Occurred());
		goto Done;
	}

	num = PyTuple_GetItem(tuple, 0);	/* leftover days */
	if (num == NULL)
		goto Done;
	Py_INCREF(num);
	temp = PyLong_AsLong(num);
	if (temp == -1 && PyErr_Occurred())
		goto Done;
	d = (int)temp;
	if ((long)d != temp) {
		PyErr_SetString(PyExc_OverflowError, "normalized days too "
				"large to fit in a C int");
		goto Done;
	}
	result = new_delta(d, s, us, 0);

Done:
	Py_XDECREF(tuple);
	Py_XDECREF(num);
	return result;
}

static PyObject *
multiply_int_timedelta(PyObject *intobj, PyDateTime_Delta *delta)
{
	PyObject *pyus_in;
	PyObject *pyus_out;
	PyObject *result;

	pyus_in = delta_to_microseconds(delta);
	if (pyus_in == NULL)
		return NULL;

	pyus_out = PyNumber_Multiply(pyus_in, intobj);
	Py_DECREF(pyus_in);
	if (pyus_out == NULL)
		return NULL;

	result = microseconds_to_delta(pyus_out);
	Py_DECREF(pyus_out);
	return result;
}

static PyObject *
divide_timedelta_int(PyDateTime_Delta *delta, PyObject *intobj)
{
	PyObject *pyus_in;
	PyObject *pyus_out;
	PyObject *result;

	pyus_in = delta_to_microseconds(delta);
	if (pyus_in == NULL)
		return NULL;

	pyus_out = PyNumber_FloorDivide(pyus_in, intobj);
	Py_DECREF(pyus_in);
	if (pyus_out == NULL)
		return NULL;

	result = microseconds_to_delta(pyus_out);
	Py_DECREF(pyus_out);
	return result;
}

static PyObject *
delta_add(PyObject *left, PyObject *right)
{
	PyObject *result = Py_NotImplemented;

	if (PyDelta_Check(left) && PyDelta_Check(right)) {
		/* delta + delta */
		/* The C-level additions can't overflow because of the
		 * invariant bounds.
		 */
		int days = GET_TD_DAYS(left) + GET_TD_DAYS(right);
		int seconds = GET_TD_SECONDS(left) + GET_TD_SECONDS(right);
		int microseconds = GET_TD_MICROSECONDS(left) +
				   GET_TD_MICROSECONDS(right);
		result = new_delta(days, seconds, microseconds, 1);
	}

	if (result == Py_NotImplemented)
		Py_INCREF(result);
	return result;
}

static PyObject *
delta_negative(PyDateTime_Delta *self)
{
	return new_delta(-GET_TD_DAYS(self),
			 -GET_TD_SECONDS(self),
			 -GET_TD_MICROSECONDS(self),
			 1);
}

static PyObject *
delta_positive(PyDateTime_Delta *self)
{
	/* Could optimize this (by returning self) if this isn't a
	 * subclass -- but who uses unary + ?  Approximately nobody.
	 */
	return new_delta(GET_TD_DAYS(self),
			 GET_TD_SECONDS(self),
			 GET_TD_MICROSECONDS(self),
			 0);
}

static PyObject *
delta_abs(PyDateTime_Delta *self)
{
	PyObject *result;

	assert(GET_TD_MICROSECONDS(self) >= 0);
	assert(GET_TD_SECONDS(self) >= 0);

	if (GET_TD_DAYS(self) < 0)
		result = delta_negative(self);
	else
		result = delta_positive(self);

	return result;
}

static PyObject *
delta_subtract(PyObject *left, PyObject *right)
{
	PyObject *result = Py_NotImplemented;

	if (PyDelta_Check(left) && PyDelta_Check(right)) {
	    	/* delta - delta */
	    	PyObject *minus_right = PyNumber_Negative(right);
	    	if (minus_right) {
	    		result = delta_add(left, minus_right);
	    		Py_DECREF(minus_right);
	    	}
	    	else
	    		result = NULL;
	}

	if (result == Py_NotImplemented)
		Py_INCREF(result);
	return result;
}

/* This is more natural as a tp_compare, but doesn't work then:  for whatever
 * reason, Python's try_3way_compare ignores tp_compare unless
 * PyInstance_Check returns true, but these aren't old-style classes.
 */
static PyObject *
delta_richcompare(PyDateTime_Delta *self, PyObject *other, int op)
{
	int diff;

	if (! PyDelta_CheckExact(other)) {
		PyErr_Format(PyExc_TypeError,
			     "can't compare %s to %s instance",
			     self->ob_type->tp_name, other->ob_type->tp_name);
		return NULL;
	}
	diff = GET_TD_DAYS(self) - GET_TD_DAYS(other);
	if (diff == 0) {
		diff = GET_TD_SECONDS(self) - GET_TD_SECONDS(other);
		if (diff == 0)
			diff = GET_TD_MICROSECONDS(self) -
			       GET_TD_MICROSECONDS(other);
	}
	return diff_to_bool(diff, op);
}

static PyObject *delta_getstate(PyDateTime_Delta *self);

static long
delta_hash(PyDateTime_Delta *self)
{
	if (self->hashcode == -1) {
		PyObject *temp = delta_getstate(self);
		if (temp != NULL) {
			self->hashcode = PyObject_Hash(temp);
			Py_DECREF(temp);
		}
	}
	return self->hashcode;
}

static PyObject *
delta_multiply(PyObject *left, PyObject *right)
{
	PyObject *result = Py_NotImplemented;

	if (PyDelta_Check(left)) {
		/* delta * ??? */
		if (PyInt_Check(right) || PyLong_Check(right))
			result = multiply_int_timedelta(right,
					(PyDateTime_Delta *) left);
	}
	else if (PyInt_Check(left) || PyLong_Check(left))
		result = multiply_int_timedelta(left,
						(PyDateTime_Delta *) right);

	if (result == Py_NotImplemented)
		Py_INCREF(result);
	return result;
}

static PyObject *
delta_divide(PyObject *left, PyObject *right)
{
	PyObject *result = Py_NotImplemented;

	if (PyDelta_Check(left)) {
		/* delta * ??? */
		if (PyInt_Check(right) || PyLong_Check(right))
			result = divide_timedelta_int(
					(PyDateTime_Delta *)left,
					right);
	}

	if (result == Py_NotImplemented)
		Py_INCREF(result);
	return result;
}

/* Fold in the value of the tag ("seconds", "weeks", etc) component of a
 * timedelta constructor.  sofar is the # of microseconds accounted for
 * so far, and there are factor microseconds per current unit, the number
 * of which is given by num.  num * factor is added to sofar in a
 * numerically careful way, and that's the result.  Any fractional
 * microseconds left over (this can happen if num is a float type) are
 * added into *leftover.
 * Note that there are many ways this can give an error (NULL) return.
 */
static PyObject *
accum(const char* tag, PyObject *sofar, PyObject *num, PyObject *factor,
      double *leftover)
{
	PyObject *prod;
	PyObject *sum;

	assert(num != NULL);

	if (PyInt_Check(num) || PyLong_Check(num)) {
		prod = PyNumber_Multiply(num, factor);
		if (prod == NULL)
			return NULL;
		sum = PyNumber_Add(sofar, prod);
		Py_DECREF(prod);
		return sum;
	}

	if (PyFloat_Check(num)) {
		double dnum;
		double fracpart;
		double intpart;
		PyObject *x;
		PyObject *y;

		/* The Plan:  decompose num into an integer part and a
		 * fractional part, num = intpart + fracpart.
		 * Then num * factor ==
		 *      intpart * factor + fracpart * factor
		 * and the LHS can be computed exactly in long arithmetic.
		 * The RHS is again broken into an int part and frac part.
		 * and the frac part is added into *leftover.
		 */
		dnum = PyFloat_AsDouble(num);
		if (dnum == -1.0 && PyErr_Occurred())
			return NULL;
		fracpart = modf(dnum, &intpart);
		x = PyLong_FromDouble(intpart);
		if (x == NULL)
			return NULL;

		prod = PyNumber_Multiply(x, factor);
		Py_DECREF(x);
		if (prod == NULL)
			return NULL;

		sum = PyNumber_Add(sofar, prod);
		Py_DECREF(prod);
		if (sum == NULL)
			return NULL;

		if (fracpart == 0.0)
			return sum;
		/* So far we've lost no information.  Dealing with the
		 * fractional part requires float arithmetic, and may
		 * lose a little info.
		 */
		assert(PyInt_Check(factor) || PyLong_Check(factor));
		if (PyInt_Check(factor))
			dnum = (double)PyInt_AsLong(factor);
		else
			dnum = PyLong_AsDouble(factor);

		dnum *= fracpart;
		fracpart = modf(dnum, &intpart);
		x = PyLong_FromDouble(intpart);
		if (x == NULL) {
			Py_DECREF(sum);
			return NULL;
		}

		y = PyNumber_Add(sum, x);
		Py_DECREF(sum);
		Py_DECREF(x);
		*leftover += fracpart;
		return y;
	}

	PyErr_Format(PyExc_TypeError,
		     "unsupported type for timedelta %s component: %s",
		     tag, num->ob_type->tp_name);
	return NULL;
}

static PyObject *
delta_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;

	/* Argument objects. */
	PyObject *day = NULL;
	PyObject *second = NULL;
	PyObject *us = NULL;
	PyObject *ms = NULL;
	PyObject *minute = NULL;
	PyObject *hour = NULL;
	PyObject *week = NULL;

	PyObject *x = NULL;	/* running sum of microseconds */
	PyObject *y = NULL;	/* temp sum of microseconds */
	double leftover_us = 0.0;

	static char *keywords[] = {
		"days", "seconds", "microseconds", "milliseconds",
		"minutes", "hours", "weeks", NULL
	};

	if (PyArg_ParseTupleAndKeywords(args, kw, "|OOOOOOO:__new__",
					keywords,
					&day, &second, &us,
					&ms, &minute, &hour, &week) == 0)
		goto Done;

	x = PyInt_FromLong(0);
	if (x == NULL)
		goto Done;

#define CLEANUP 	\
	Py_DECREF(x);	\
	x = y;		\
	if (x == NULL)	\
		goto Done

	if (us) {
		y = accum("microseconds", x, us, us_per_us, &leftover_us);
		CLEANUP;
	}
	if (ms) {
		y = accum("milliseconds", x, ms, us_per_ms, &leftover_us);
		CLEANUP;
	}
	if (second) {
		y = accum("seconds", x, second, us_per_second, &leftover_us);
		CLEANUP;
	}
	if (minute) {
		y = accum("minutes", x, minute, us_per_minute, &leftover_us);
		CLEANUP;
	}
	if (hour) {
		y = accum("hours", x, hour, us_per_hour, &leftover_us);
		CLEANUP;
	}
	if (day) {
		y = accum("days", x, day, us_per_day, &leftover_us);
		CLEANUP;
	}
	if (week) {
		y = accum("weeks", x, week, us_per_week, &leftover_us);
		CLEANUP;
	}
	if (leftover_us) {
		/* Round to nearest whole # of us, and add into x. */
		PyObject *temp;
		if (leftover_us >= 0.0)
			leftover_us = floor(leftover_us + 0.5);
		else
			leftover_us = ceil(leftover_us - 0.5);
		temp = PyLong_FromDouble(leftover_us);
		if (temp == NULL) {
			Py_DECREF(x);
			goto Done;
		}
		y = PyNumber_Add(x, temp);
		Py_DECREF(temp);
		CLEANUP;
	}

	self = microseconds_to_delta(x);
	Py_DECREF(x);
Done:
	return self;

#undef CLEANUP
}

static int
delta_nonzero(PyDateTime_Delta *self)
{
	return (GET_TD_DAYS(self) != 0
		|| GET_TD_SECONDS(self) != 0
		|| GET_TD_MICROSECONDS(self) != 0);
}

static PyObject *
delta_repr(PyDateTime_Delta *self)
{
	if (GET_TD_MICROSECONDS(self) != 0)
		return PyString_FromFormat("%s(%d, %d, %d)",
					   self->ob_type->tp_name,
					   GET_TD_DAYS(self),
					   GET_TD_SECONDS(self),
					   GET_TD_MICROSECONDS(self));
	if (GET_TD_SECONDS(self) != 0)
		return PyString_FromFormat("%s(%d, %d)",
					   self->ob_type->tp_name,
					   GET_TD_DAYS(self),
					   GET_TD_SECONDS(self));

	return PyString_FromFormat("%s(%d)",
				   self->ob_type->tp_name,
				   GET_TD_DAYS(self));
}

static PyObject *
delta_str(PyDateTime_Delta *self)
{
	int days = GET_TD_DAYS(self);
	int seconds = GET_TD_SECONDS(self);
	int us = GET_TD_MICROSECONDS(self);
	int hours;
	int minutes;
	char buf[100];
	char *pbuf = buf;
	size_t buflen = sizeof(buf);
	int n;

	minutes = divmod(seconds, 60, &seconds);
	hours = divmod(minutes, 60, &minutes);

	if (days) {
		n = PyOS_snprintf(pbuf, buflen, "%d day%s, ", days,
				  (days == 1 || days == -1) ? "" : "s");
		if (n < 0 || (size_t)n >= buflen)
			goto Fail;
		pbuf += n;
		buflen -= (size_t)n;
	}

	n = PyOS_snprintf(pbuf, buflen, "%d:%02d:%02d",
			  hours, minutes, seconds);
	if (n < 0 || (size_t)n >= buflen)
		goto Fail;
	pbuf += n;
	buflen -= (size_t)n;

	if (us) {
		n = PyOS_snprintf(pbuf, buflen, ".%06d", us);
		if (n < 0 || (size_t)n >= buflen)
			goto Fail;
		pbuf += n;
	}

	return PyString_FromStringAndSize(buf, pbuf - buf);

 Fail:
	PyErr_SetString(PyExc_SystemError, "goofy result from PyOS_snprintf");
	return NULL;
}

/* Pickle support.  Quite a maze!  While __getstate__/__setstate__ sufficed
 * in the Python implementation, the C implementation also requires
 * __reduce__, and a __safe_for_unpickling__ attr in the type object.
 */
static PyObject *
delta_getstate(PyDateTime_Delta *self)
{
	return Py_BuildValue("iii", GET_TD_DAYS(self),
				    GET_TD_SECONDS(self),
				    GET_TD_MICROSECONDS(self));
}

static PyObject *
delta_setstate(PyDateTime_Delta *self, PyObject *state)
{
	int day;
	int second;
	int us;

	if (!PyArg_ParseTuple(state, "iii:__setstate__", &day, &second, &us))
		return NULL;

	self->hashcode = -1;
	SET_TD_DAYS(self, day);
	SET_TD_SECONDS(self, second);
	SET_TD_MICROSECONDS(self, us);

	Py_INCREF(Py_None);
	return Py_None;
}

static PyObject *
delta_reduce(PyDateTime_Delta* self)
{
	PyObject* result = NULL;
	PyObject* state  = delta_getstate(self);

	if (state != NULL) {
		/* The funky "()" in the format string creates an empty
		 * tuple as the 2nd component of the result 3-tuple.
		 */
		result = Py_BuildValue("O()O", self->ob_type, state);
		Py_DECREF(state);
	}
	return result;
}

#define OFFSET(field)  offsetof(PyDateTime_Delta, field)

static PyMemberDef delta_members[] = {
	{"days",         T_INT, OFFSET(days),         READONLY,
	 PyDoc_STR("Number of days.")},

	{"seconds",      T_INT, OFFSET(seconds),      READONLY,
	 PyDoc_STR("Number of seconds (>= 0 and less than 1 day).")},

	{"microseconds", T_INT, OFFSET(microseconds), READONLY,
	 PyDoc_STR("Number of microseconds (>= 0 and less than 1 second).")},
	{NULL}
};

static PyMethodDef delta_methods[] = {
	{"__setstate__", (PyCFunction)delta_setstate, METH_O,
	 PyDoc_STR("__setstate__(state)")},

	{"__reduce__", (PyCFunction)delta_reduce,     METH_NOARGS,
	 PyDoc_STR("__setstate__(state)")},

	{"__getstate__", (PyCFunction)delta_getstate, METH_NOARGS,
	 PyDoc_STR("__getstate__() -> state")},
	{NULL,	NULL},
};

static char delta_doc[] =
PyDoc_STR("Difference between two datetime values.");

static PyNumberMethods delta_as_number = {
	delta_add,				/* nb_add */
	delta_subtract,				/* nb_subtract */
	delta_multiply,				/* nb_multiply */
	delta_divide,				/* nb_divide */
	0,					/* nb_remainder */
	0,					/* nb_divmod */
	0,					/* nb_power */
	(unaryfunc)delta_negative,		/* nb_negative */
	(unaryfunc)delta_positive,		/* nb_positive */
	(unaryfunc)delta_abs,			/* nb_absolute */
	(inquiry)delta_nonzero,			/* nb_nonzero */
	0,					/*nb_invert*/
	0,					/*nb_lshift*/
	0,					/*nb_rshift*/
	0,					/*nb_and*/
	0,					/*nb_xor*/
	0,					/*nb_or*/
	0,					/*nb_coerce*/
	0,					/*nb_int*/
	0,					/*nb_long*/
	0,					/*nb_float*/
	0,					/*nb_oct*/
	0, 					/*nb_hex*/
	0,					/*nb_inplace_add*/
	0,					/*nb_inplace_subtract*/
	0,					/*nb_inplace_multiply*/
	0,					/*nb_inplace_divide*/
	0,					/*nb_inplace_remainder*/
	0,					/*nb_inplace_power*/
	0,					/*nb_inplace_lshift*/
	0,					/*nb_inplace_rshift*/
	0,					/*nb_inplace_and*/
	0,					/*nb_inplace_xor*/
	0,					/*nb_inplace_or*/
	delta_divide,				/* nb_floor_divide */
	0,					/* nb_true_divide */
	0,					/* nb_inplace_floor_divide */
	0,					/* nb_inplace_true_divide */
};

static PyTypeObject PyDateTime_DeltaType = {
	PyObject_HEAD_INIT(NULL)
	0,						/* ob_size */
	"datetime.timedelta",				/* tp_name */
	sizeof(PyDateTime_Delta),			/* tp_basicsize */
	0,						/* tp_itemsize */
	0,						/* tp_dealloc */
	0,						/* tp_print */
	0,						/* tp_getattr */
	0,						/* tp_setattr */
	0,						/* tp_compare */
	(reprfunc)delta_repr,				/* tp_repr */
	&delta_as_number,				/* tp_as_number */
	0,						/* tp_as_sequence */
	0,						/* tp_as_mapping */
	(hashfunc)delta_hash,				/* tp_hash */
	0,              				/* tp_call */
	(reprfunc)delta_str,				/* tp_str */
	PyObject_GenericGetAttr,			/* tp_getattro */
	0,						/* tp_setattro */
	0,						/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES,	/* tp_flags */
	delta_doc,					/* tp_doc */
	0,						/* tp_traverse */
	0,						/* tp_clear */
	(richcmpfunc)delta_richcompare,			/* tp_richcompare */
	0,						/* tp_weaklistoffset */
	0,						/* tp_iter */
	0,						/* tp_iternext */
	delta_methods,					/* tp_methods */
	delta_members,					/* tp_members */
	0,						/* tp_getset */
	0,						/* tp_base */
	0,						/* tp_dict */
	0,						/* tp_descr_get */
	0,						/* tp_descr_set */
	0,						/* tp_dictoffset */
	0,						/* tp_init */
	0,						/* tp_alloc */
	delta_new,					/* tp_new */
	_PyObject_Del,					/* tp_free */
};

/*
 * PyDateTime_Date implementation.
 */

/* Accessor properties. */

static PyObject *
date_year(PyDateTime_Date *self, void *unused)
{
	return PyInt_FromLong(GET_YEAR(self));
}

static PyObject *
date_month(PyDateTime_Date *self, void *unused)
{
	return PyInt_FromLong(GET_MONTH(self));
}

static PyObject *
date_day(PyDateTime_Date *self, void *unused)
{
	return PyInt_FromLong(GET_DAY(self));
}

static PyGetSetDef date_getset[] = {
	{"year",        (getter)date_year},
	{"month",       (getter)date_month},
	{"day",         (getter)date_day},
	{NULL}
};

/* Constructors. */

static PyObject *
date_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	int year;
	int month;
	int day;

	static char *keywords[] = {
		"year", "month", "day", NULL
	};

	if (PyArg_ParseTupleAndKeywords(args, kw, "iii", keywords,
					&year, &month, &day)) {
		if (check_date_args(year, month, day) < 0)
			return NULL;
		self = new_date(year, month, day);
	}
	return self;
}

/* Return new date from localtime(t). */
static PyObject *
date_local_from_time_t(PyObject *cls, time_t t)
{
	struct tm *tm;
	PyObject *result = NULL;

	tm = localtime(&t);
	if (tm)
		result = PyObject_CallFunction(cls, "iii",
					       tm->tm_year + 1900,
					       tm->tm_mon + 1,
					       tm->tm_mday);
	else
		PyErr_SetString(PyExc_ValueError,
				"timestamp out of range for "
				"platform localtime() function");
	return result;
}

/* Return new date from current time.
 * We say this is equivalent to fromtimestamp(time.time()), and the
 * only way to be sure of that is to *call* time.time().  That's not
 * generally the same as calling C's time.
 */
static PyObject *
date_today(PyObject *cls, PyObject *dummy)
{
	PyObject *time;
	PyObject *result;

	time = time_time();
	if (time == NULL)
		return NULL;

	/* Note well:  today() is a class method, so this may not call
	 * date.fromtimestamp.  For example, it may call
	 * datetime.fromtimestamp.  That's why we need all the accuracy
	 * time.time() delivers; if someone were gonzo about optimization,
	 * date.today() could get away with plain C time().
	 */
	result = PyObject_CallMethod(cls, "fromtimestamp", "O", time);
	Py_DECREF(time);
	return result;
}

/* Return new date from given timestamp (Python timestamp -- a double). */
static PyObject *
date_fromtimestamp(PyObject *cls, PyObject *args)
{
	double timestamp;
	PyObject *result = NULL;

	if (PyArg_ParseTuple(args, "d:fromtimestamp", &timestamp))
		result = date_local_from_time_t(cls, (time_t)timestamp);
	return result;
}

/* Return new date from proleptic Gregorian ordinal.  Raises ValueError if
 * the ordinal is out of range.
 */
static PyObject *
date_fromordinal(PyObject *cls, PyObject *args)
{
	PyObject *result = NULL;
	int ordinal;

	if (PyArg_ParseTuple(args, "i:fromordinal", &ordinal)) {
		int year;
		int month;
		int day;

		if (ordinal < 1)
			PyErr_SetString(PyExc_ValueError, "ordinal must be "
							  ">= 1");
		else {
			ord_to_ymd(ordinal, &year, &month, &day);
			result = PyObject_CallFunction(cls, "iii",
						       year, month, day);
		}
	}
	return result;
}

/*
 * Date arithmetic.
 */

/* date + timedelta -> date.  If arg negate is true, subtract the timedelta
 * instead.
 */
static PyObject *
add_date_timedelta(PyDateTime_Date *date, PyDateTime_Delta *delta, int negate)
{
	PyObject *result = NULL;
	int year = GET_YEAR(date);
	int month = GET_MONTH(date);
	int deltadays = GET_TD_DAYS(delta);
	/* C-level overflow is impossible because |deltadays| < 1e9. */
	int day = GET_DAY(date) + (negate ? -deltadays : deltadays);

	if (normalize_date(&year, &month, &day) >= 0)
		result = new_date(year, month, day);
	return result;
}

static PyObject *
date_add(PyObject *left, PyObject *right)
{
	if (PyDateTime_Check(left) || PyDateTime_Check(right)) {
		Py_INCREF(Py_NotImplemented);
		return Py_NotImplemented;
	}
	if (PyDate_CheckExact(left)) {
		/* date + ??? */
		if (PyDelta_Check(right))
			/* date + delta */
			return add_date_timedelta((PyDateTime_Date *) left,
						  (PyDateTime_Delta *) right,
						  0);
	}
	else {
		/* ??? + date
		 * 'right' must be one of us, or we wouldn't have been called
		 */
		if (PyDelta_Check(left))
			/* delta + date */
			return add_date_timedelta((PyDateTime_Date *) right,
						  (PyDateTime_Delta *) left,
						  0);
	}
	Py_INCREF(Py_NotImplemented);
	return Py_NotImplemented;
}

static PyObject *
date_subtract(PyObject *left, PyObject *right)
{
	if (PyDateTime_Check(left) || PyDateTime_Check(right)) {
		Py_INCREF(Py_NotImplemented);
		return Py_NotImplemented;
	}
	if (PyDate_CheckExact(left)) {
		if (PyDate_CheckExact(right)) {
			/* date - date */
			int left_ord = ymd_to_ord(GET_YEAR(left),
						  GET_MONTH(left),
						  GET_DAY(left));
			int right_ord = ymd_to_ord(GET_YEAR(right),
						   GET_MONTH(right),
						   GET_DAY(right));
			return new_delta(left_ord - right_ord, 0, 0, 0);
		}
		if (PyDelta_Check(right)) {
			/* date - delta */
			return add_date_timedelta((PyDateTime_Date *) left,
						  (PyDateTime_Delta *) right,
						  1);
		}
	}
	Py_INCREF(Py_NotImplemented);
	return Py_NotImplemented;
}


/* Various ways to turn a date into a string. */

static PyObject *
date_repr(PyDateTime_Date *self)
{
	char buffer[1028];
	char *typename;

	typename = self->ob_type->tp_name;
	PyOS_snprintf(buffer, sizeof(buffer), "%s(%d, %d, %d)",
		      typename,
		      GET_YEAR(self), GET_MONTH(self), GET_DAY(self));

	return PyString_FromString(buffer);
}

static PyObject *
date_isoformat(PyDateTime_Date *self)
{
	char buffer[128];

	isoformat_date(self, buffer, sizeof(buffer));
	return PyString_FromString(buffer);
}

/* str() calls the appropriate isofomat() method. */
static PyObject *
date_str(PyDateTime_Date *self)
{
	return PyObject_CallMethod((PyObject *)self, "isoformat", "()");
}


static PyObject *
date_ctime(PyDateTime_Date *self)
{
	return format_ctime(self, 0, 0, 0);
}

static PyObject *
date_strftime(PyDateTime_Date *self, PyObject *args, PyObject *kw)
{
	/* This method can be inherited, and needs to call the
	 * timetuple() method appropriate to self's class.
	 */
	PyObject *result;
	PyObject *format;
	PyObject *tuple;
	static char *keywords[] = {"format", NULL};

	if (! PyArg_ParseTupleAndKeywords(args, kw, "O!:strftime", keywords,
					  &PyString_Type, &format))
		return NULL;

	tuple = PyObject_CallMethod((PyObject *)self, "timetuple", "()");
	if (tuple == NULL)
		return NULL;
	result = wrap_strftime((PyObject *)self, format, tuple);
	Py_DECREF(tuple);
	return result;
}

/* ISO methods. */

static PyObject *
date_isoweekday(PyDateTime_Date *self)
{
	int dow = weekday(GET_YEAR(self), GET_MONTH(self), GET_DAY(self));

	return PyInt_FromLong(dow + 1);
}

static PyObject *
date_isocalendar(PyDateTime_Date *self)
{
	int  year         = GET_YEAR(self);
	int  week1_monday = iso_week1_monday(year);
	int today         = ymd_to_ord(year, GET_MONTH(self), GET_DAY(self));
	int  week;
	int  day;

	week = divmod(today - week1_monday, 7, &day);
	if (week < 0) {
		--year;
		week1_monday = iso_week1_monday(year);
		week = divmod(today - week1_monday, 7, &day);
	}
	else if (week >= 52 && today >= iso_week1_monday(year + 1)) {
		++year;
		week = 0;
	}
	return Py_BuildValue("iii", year, week + 1, day + 1);
}

/* Miscellaneous methods. */

/* This is more natural as a tp_compare, but doesn't work then:  for whatever
 * reason, Python's try_3way_compare ignores tp_compare unless
 * PyInstance_Check returns true, but these aren't old-style classes.
 */
static PyObject *
date_richcompare(PyDateTime_Date *self, PyObject *other, int op)
{
	int diff;

	if (! PyDate_Check(other)) {
		PyErr_Format(PyExc_TypeError,
			     "can't compare date to %s instance",
			     other->ob_type->tp_name);
		return NULL;
	}
	diff = memcmp(self->data, ((PyDateTime_Date *)other)->data,
		      _PyDateTime_DATE_DATASIZE);
	return diff_to_bool(diff, op);
}

static PyObject *
date_timetuple(PyDateTime_Date *self)
{
	return build_struct_time(GET_YEAR(self),
				 GET_MONTH(self),
				 GET_DAY(self),
				 0, 0, 0, -1);
}

static PyObject *date_getstate(PyDateTime_Date *self);

static long
date_hash(PyDateTime_Date *self)
{
	if (self->hashcode == -1) {
		PyObject *temp = date_getstate(self);
		if (temp != NULL) {
			self->hashcode = PyObject_Hash(temp);
			Py_DECREF(temp);
		}
	}
	return self->hashcode;
}

static PyObject *
date_toordinal(PyDateTime_Date *self)
{
	return PyInt_FromLong(ymd_to_ord(GET_YEAR(self), GET_MONTH(self),
					 GET_DAY(self)));
}

static PyObject *
date_weekday(PyDateTime_Date *self)
{
	int dow = weekday(GET_YEAR(self), GET_MONTH(self), GET_DAY(self));

	return PyInt_FromLong(dow);
}

/* Pickle support.  Quite a maze! */

static PyObject *
date_getstate(PyDateTime_Date *self)
{
	return PyString_FromStringAndSize(self->data,
					  _PyDateTime_DATE_DATASIZE);
}

static PyObject *
date_setstate(PyDateTime_Date *self, PyObject *state)
{
	const int len = PyString_Size(state);
	unsigned char *pdata = (unsigned char*)PyString_AsString(state);

	if (! PyString_Check(state) ||
	    len != _PyDateTime_DATE_DATASIZE) {
		PyErr_SetString(PyExc_TypeError,
				"bad argument to date.__setstate__");
		return NULL;
	}
	memcpy(self->data, pdata, _PyDateTime_DATE_DATASIZE);
	self->hashcode = -1;

	Py_INCREF(Py_None);
	return Py_None;
}

/* XXX This seems a ridiculously inefficient way to pickle a short string. */
static PyObject *
date_pickler(PyObject *module, PyDateTime_Date *date)
{
	PyObject *state;
	PyObject *result = NULL;

	if (! PyDate_CheckExact(date)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to date pickler: %s",
			     date->ob_type->tp_name);
		return NULL;
	}
	state = date_getstate(date);
	if (state) {
		result = Py_BuildValue("O(O)", date_unpickler_object, state);
		Py_DECREF(state);
	}
	return result;
}

static PyObject *
date_unpickler(PyObject *module, PyObject *arg)
{
	PyDateTime_Date *self;

	if (! PyString_CheckExact(arg)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to date unpickler: %s",
			     arg->ob_type->tp_name);
		return NULL;
	}
	self = PyObject_New(PyDateTime_Date, &PyDateTime_DateType);
	if (self != NULL) {
		PyObject *res = date_setstate(self, arg);
		if (res == NULL) {
			Py_DECREF(self);
			return NULL;
		}
		Py_DECREF(res);
	}
	return (PyObject *)self;
}

static PyMethodDef date_methods[] = {
	/* Class methods: */
	{"fromtimestamp", (PyCFunction)date_fromtimestamp, METH_VARARGS |
							   METH_CLASS,
	 PyDoc_STR("timestamp -> local date from a POSIX timestamp (like "
	 	   "time.time()).")},

	{"fromordinal", (PyCFunction)date_fromordinal,	METH_VARARGS |
							METH_CLASS,
	 PyDoc_STR("int -> date corresponding to a proleptic Gregorian "
	 	   "ordinal.")},

	{"today",         (PyCFunction)date_today,   METH_NOARGS | METH_CLASS,
	 PyDoc_STR("Current date or datetime:  same as "
	 	   "self.__class__.fromtimestamp(time.time()).")},

	/* Instance methods: */

	{"ctime",       (PyCFunction)date_ctime,        METH_NOARGS,
	 PyDoc_STR("Return ctime() style string.")},

	{"strftime",   	(PyCFunction)date_strftime,	METH_KEYWORDS,
	 PyDoc_STR("format -> strftime() style string.")},

	{"timetuple",   (PyCFunction)date_timetuple,    METH_NOARGS,
         PyDoc_STR("Return time tuple, compatible with time.localtime().")},

	{"isocalendar", (PyCFunction)date_isocalendar,  METH_NOARGS,
	 PyDoc_STR("Return a 3-tuple containing ISO year, week number, and "
	 	   "weekday.")},

	{"isoformat",   (PyCFunction)date_isoformat,	METH_NOARGS,
	 PyDoc_STR("Return string in ISO 8601 format, YYYY-MM-DD.")},

	{"isoweekday",  (PyCFunction)date_isoweekday,   METH_NOARGS,
	 PyDoc_STR("Return the day of the week represented by the date.\n"
	 	   "Monday == 1 ... Sunday == 7")},

	{"toordinal",   (PyCFunction)date_toordinal,    METH_NOARGS,
	 PyDoc_STR("Return proleptic Gregorian ordinal.  January 1 of year "
	 	   "1 is day 1.")},

	{"weekday",     (PyCFunction)date_weekday,      METH_NOARGS,
	 PyDoc_STR("Return the day of the week represented by the date.\n"
		   "Monday == 0 ... Sunday == 6")},

	{"__setstate__", (PyCFunction)date_setstate,	METH_O,
	 PyDoc_STR("__setstate__(state)")},

	{"__getstate__", (PyCFunction)date_getstate,	METH_NOARGS,
	 PyDoc_STR("__getstate__() -> state")},

	{NULL,	NULL}
};

static char date_doc[] =
PyDoc_STR("Basic date type.");

static PyNumberMethods date_as_number = {
	date_add,					/* nb_add */
	date_subtract,					/* nb_subtract */
	0,						/* nb_multiply */
	0,						/* nb_divide */
	0,						/* nb_remainder */
	0,						/* nb_divmod */
	0,						/* nb_power */
	0,						/* nb_negative */
	0,						/* nb_positive */
	0,						/* nb_absolute */
	0,						/* nb_nonzero */
};

static PyTypeObject PyDateTime_DateType = {
	PyObject_HEAD_INIT(NULL)
	0,						/* ob_size */
	"datetime.date",				/* tp_name */
	sizeof(PyDateTime_Date),			/* tp_basicsize */
	0,						/* tp_itemsize */
	(destructor)PyObject_Del,			/* tp_dealloc */
	0,						/* tp_print */
	0,						/* tp_getattr */
	0,						/* tp_setattr */
	0,						/* tp_compare */
	(reprfunc)date_repr,				/* tp_repr */
	&date_as_number,				/* tp_as_number */
	0,						/* tp_as_sequence */
	0,						/* tp_as_mapping */
	(hashfunc)date_hash,				/* tp_hash */
	0,              				/* tp_call */
	(reprfunc)date_str,				/* tp_str */
	PyObject_GenericGetAttr,			/* tp_getattro */
	0,						/* tp_setattro */
	0,						/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
        Py_TPFLAGS_BASETYPE,				/* tp_flags */
	date_doc,					/* tp_doc */
	0,						/* tp_traverse */
	0,						/* tp_clear */
	(richcmpfunc)date_richcompare,			/* tp_richcompare */
	0,						/* tp_weaklistoffset */
	0,						/* tp_iter */
	0,						/* tp_iternext */
	date_methods,					/* tp_methods */
	0,						/* tp_members */
	date_getset,					/* tp_getset */
	0,						/* tp_base */
	0,						/* tp_dict */
	0,						/* tp_descr_get */
	0,						/* tp_descr_set */
	0,						/* tp_dictoffset */
	0,						/* tp_init */
	0,						/* tp_alloc */
	date_new,					/* tp_new */
	_PyObject_Del,					/* tp_free */
};

/*
 * PyDateTime_DateTime implementation.
 */

/* Accessor properties. */

static PyObject *
datetime_hour(PyDateTime_DateTime *self, void *unused)
{
	return PyInt_FromLong(DATE_GET_HOUR(self));
}

static PyObject *
datetime_minute(PyDateTime_DateTime *self, void *unused)
{
	return PyInt_FromLong(DATE_GET_MINUTE(self));
}

static PyObject *
datetime_second(PyDateTime_DateTime *self, void *unused)
{
	return PyInt_FromLong(DATE_GET_SECOND(self));
}

static PyObject *
datetime_microsecond(PyDateTime_DateTime *self, void *unused)
{
	return PyInt_FromLong(DATE_GET_MICROSECOND(self));
}

static PyGetSetDef datetime_getset[] = {
	{"hour",        (getter)datetime_hour},
	{"minute",      (getter)datetime_minute},
	{"second",      (getter)datetime_second},
	{"microsecond", (getter)datetime_microsecond},
	{NULL}
};

/* Constructors. */

static PyObject *
datetime_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	int year;
	int month;
	int day;
	int hour = 0;
	int minute = 0;
	int second = 0;
	int usecond = 0;

	static char *keywords[] = {
		"year", "month", "day", "hour", "minute", "second",
		"microsecond", NULL
	};

	if (PyArg_ParseTupleAndKeywords(args, kw, "iii|iiii", keywords,
					&year, &month, &day, &hour, &minute,
					&second, &usecond)) {
		if (check_date_args(year, month, day) < 0)
			return NULL;
		if (check_time_args(hour, minute, second, usecond) < 0)
			return NULL;
		self = new_datetime(year, month, day,
				    hour, minute, second, usecond);
	}
	return self;
}


/* TM_FUNC is the shared type of localtime() and gmtime(). */
typedef struct tm *(*TM_FUNC)(const time_t *timer);

/* Internal helper.
 * Build datetime from a time_t and a distinct count of microseconds.
 * Pass localtime or gmtime for f, to control the interpretation of timet.
 */
static PyObject *
datetime_from_timet_and_us(PyObject *cls, TM_FUNC f, time_t timet, int us)
{
	struct tm *tm;
	PyObject *result = NULL;

	tm = f(&timet);
	if (tm)
		result = PyObject_CallFunction(cls, "iiiiiii",
					       tm->tm_year + 1900,
					       tm->tm_mon + 1,
					       tm->tm_mday,
					       tm->tm_hour,
					       tm->tm_min,
					       tm->tm_sec,
					       us);
	else
		PyErr_SetString(PyExc_ValueError,
				"timestamp out of range for "
				"platform localtime()/gmtime() function");
	return result;
}

/* Internal helper.
 * Build datetime from a Python timestamp.  Pass localtime or gmtime for f,
 * to control the interpretation of the timestamp.  Since a double doesn't
 * have enough bits to cover a datetime's full range of precision, it's
 * better to call datetime_from_timet_and_us provided you have a way
 * to get that much precision (e.g., C time() isn't good enough).
 */
static PyObject *
datetime_from_timestamp(PyObject *cls, TM_FUNC f, double timestamp)
{
	time_t timet = (time_t)timestamp;
	int us = (int)((timestamp - (double)timet) * 1e6);

	return datetime_from_timet_and_us(cls, f, timet, us);
}

/* Internal helper.
 * Build most accurate possible datetime for current time.  Pass localtime or
 * gmtime for f as appropriate.
 */
static PyObject *
datetime_best_possible(PyObject *cls, TM_FUNC f)
{
#ifdef HAVE_GETTIMEOFDAY
	struct timeval t;

#ifdef GETTIMEOFDAY_NO_TZ
	gettimeofday(&t);
#else
	gettimeofday(&t, (struct timezone *)NULL);
#endif
	return datetime_from_timet_and_us(cls, f, t.tv_sec, (int)t.tv_usec);

#else	/* ! HAVE_GETTIMEOFDAY */
	/* No flavor of gettimeofday exists on this platform.  Python's
	 * time.time() does a lot of other platform tricks to get the
	 * best time it can on the platform, and we're not going to do
	 * better than that (if we could, the better code would belong
	 * in time.time()!)  We're limited by the precision of a double,
	 * though.
	 */
	PyObject *time;
	double dtime;

	time = time_time();
    	if (time == NULL)
    		return NULL;
	dtime = PyFloat_AsDouble(time);
	Py_DECREF(time);
	if (dtime == -1.0 && PyErr_Occurred())
		return NULL;
	return datetime_from_timestamp(cls, f, dtime);
#endif	/* ! HAVE_GETTIMEOFDAY */
}

/* Return new local datetime from timestamp (Python timestamp -- a double). */
static PyObject *
datetime_fromtimestamp(PyObject *cls, PyObject *args)
{
	double timestamp;
	PyObject *result = NULL;

	if (PyArg_ParseTuple(args, "d:fromtimestamp", &timestamp))
		result = datetime_from_timestamp(cls, localtime, timestamp);
	return result;
}

/* Return new UTC datetime from timestamp (Python timestamp -- a double). */
static PyObject *
datetime_utcfromtimestamp(PyObject *cls, PyObject *args)
{
	double timestamp;
	PyObject *result = NULL;

	if (PyArg_ParseTuple(args, "d:utcfromtimestamp", &timestamp))
		result = datetime_from_timestamp(cls, gmtime, timestamp);
	return result;
}

/* Return best possible local time -- this isn't constrained by the
 * precision of a timestamp.
 */
static PyObject *
datetime_now(PyObject *cls, PyObject *dummy)
{
	return datetime_best_possible(cls, localtime);
}

/* Return best possible UTC time -- this isn't constrained by the
 * precision of a timestamp.
 */
static PyObject *
datetime_utcnow(PyObject *cls, PyObject *dummy)
{
	return datetime_best_possible(cls, gmtime);
}

/* Return new datetime or datetimetz from date/datetime/datetimetz and
 * time/timetz arguments.
 */
static PyObject *
datetime_combine(PyObject *cls, PyObject *args, PyObject *kw)
{
 	static char *keywords[] = {"date", "time", NULL};
	PyObject *date;
	PyObject *time;
	PyObject *result = NULL;

	if (PyArg_ParseTupleAndKeywords(args, kw, "O!O!:combine", keywords,
					&PyDateTime_DateType, &date,
					&PyDateTime_TimeType, &time))
		result = PyObject_CallFunction(cls, "iiiiiii",
						GET_YEAR(date),
				    		GET_MONTH(date),
						GET_DAY(date),
				    		TIME_GET_HOUR(time),
				    		TIME_GET_MINUTE(time),
				    		TIME_GET_SECOND(time),
				    		TIME_GET_MICROSECOND(time));
	if (result && PyTimeTZ_Check(time) && PyDateTimeTZ_Check(result)) {
		/* Copy the tzinfo field. */
		PyObject *tzinfo = ((PyDateTime_TimeTZ *)time)->tzinfo;
		Py_INCREF(tzinfo);
		Py_DECREF(((PyDateTime_DateTimeTZ *)result)->tzinfo);
		((PyDateTime_DateTimeTZ *)result)->tzinfo = tzinfo;
	}
	return result;
}

/* datetime arithmetic. */

static PyObject *
add_datetime_timedelta(PyDateTime_DateTime *date, PyDateTime_Delta *delta)
{
	/* Note that the C-level additions can't overflow, because of
	 * invariant bounds on the member values.
	 */
	int year = GET_YEAR(date);
	int month = GET_MONTH(date);
	int day = GET_DAY(date) + GET_TD_DAYS(delta);
	int hour = DATE_GET_HOUR(date);
	int minute = DATE_GET_MINUTE(date);
	int second = DATE_GET_SECOND(date) + GET_TD_SECONDS(delta);
	int microsecond = DATE_GET_MICROSECOND(date) +
			  GET_TD_MICROSECONDS(delta);

	if (normalize_datetime(&year, &month, &day,
			       &hour, &minute, &second, &microsecond) < 0)
		return NULL;
	else
		return new_datetime(year, month, day,
				    hour, minute, second, microsecond);
}

static PyObject *
sub_datetime_timedelta(PyDateTime_DateTime *date, PyDateTime_Delta *delta)
{
	/* Note that the C-level subtractions can't overflow, because of
	 * invariant bounds on the member values.
	 */
	int year = GET_YEAR(date);
	int month = GET_MONTH(date);
	int day = GET_DAY(date) - GET_TD_DAYS(delta);
	int hour = DATE_GET_HOUR(date);
	int minute = DATE_GET_MINUTE(date);
	int second = DATE_GET_SECOND(date) - GET_TD_SECONDS(delta);
	int microsecond = DATE_GET_MICROSECOND(date) -
			  GET_TD_MICROSECONDS(delta);

	if (normalize_datetime(&year, &month, &day,
			       &hour, &minute, &second, &microsecond) < 0)
		return NULL;
	else
		return new_datetime(year, month, day,
				    hour, minute, second, microsecond);
}

static PyObject *
sub_datetime_datetime(PyDateTime_DateTime *left, PyDateTime_DateTime *right)
{
	int days1 = ymd_to_ord(GET_YEAR(left), GET_MONTH(left), GET_DAY(left));
	int days2 = ymd_to_ord(GET_YEAR(right),
			       GET_MONTH(right),
			       GET_DAY(right));
	/* These can't overflow, since the values are normalized.  At most
	 * this gives the number of seconds in one day.
	 */
	int delta_s = (DATE_GET_HOUR(left) - DATE_GET_HOUR(right)) * 3600 +
	              (DATE_GET_MINUTE(left) - DATE_GET_MINUTE(right)) * 60 +
		      DATE_GET_SECOND(left) - DATE_GET_SECOND(right);
	int delta_us = DATE_GET_MICROSECOND(left) -
		       DATE_GET_MICROSECOND(right);

	return new_delta(days1 - days2, delta_s, delta_us, 1);
}

static PyObject *
datetime_add(PyObject *left, PyObject *right)
{
	if (PyDateTime_Check(left)) {
		/* datetime + ??? */
		if (PyDelta_Check(right))
			/* datetime + delta */
			return add_datetime_timedelta(
					(PyDateTime_DateTime *)left,
					(PyDateTime_Delta *)right);
	}
	else if (PyDelta_Check(left)) {
		/* delta + datetime */
		return add_datetime_timedelta((PyDateTime_DateTime *) right,
					      (PyDateTime_Delta *) left);
	}
	Py_INCREF(Py_NotImplemented);
	return Py_NotImplemented;
}

static PyObject *
datetime_subtract(PyObject *left, PyObject *right)
{
	PyObject *result = Py_NotImplemented;

	if (PyDateTime_Check(left)) {
		/* datetime - ??? */
		if (PyDateTime_Check(right)) {
			/* datetime - datetime */
			result = sub_datetime_datetime(
					(PyDateTime_DateTime *)left,
					(PyDateTime_DateTime *)right);
		}
		else if (PyDelta_Check(right)) {
			/* datetime - delta */
			result = sub_datetime_timedelta(
					(PyDateTime_DateTime *)left,
					(PyDateTime_Delta *)right);
		}
	}

	if (result == Py_NotImplemented)
		Py_INCREF(result);
	return result;
}

/* Various ways to turn a datetime into a string. */

static PyObject *
datetime_repr(PyDateTime_DateTime *self)
{
	char buffer[1000];
	char *typename = self->ob_type->tp_name;

	if (DATE_GET_MICROSECOND(self)) {
		PyOS_snprintf(buffer, sizeof(buffer),
			      "%s(%d, %d, %d, %d, %d, %d, %d)",
			      typename,
			      GET_YEAR(self), GET_MONTH(self), GET_DAY(self),
			      DATE_GET_HOUR(self), DATE_GET_MINUTE(self),
			      DATE_GET_SECOND(self),
			      DATE_GET_MICROSECOND(self));
	}
	else if (DATE_GET_SECOND(self)) {
		PyOS_snprintf(buffer, sizeof(buffer),
			      "%s(%d, %d, %d, %d, %d, %d)",
			      typename,
			      GET_YEAR(self), GET_MONTH(self), GET_DAY(self),
			      DATE_GET_HOUR(self), DATE_GET_MINUTE(self),
			      DATE_GET_SECOND(self));
	}
	else {
		PyOS_snprintf(buffer, sizeof(buffer),
			      "%s(%d, %d, %d, %d, %d)",
			      typename,
			      GET_YEAR(self), GET_MONTH(self), GET_DAY(self),
			      DATE_GET_HOUR(self), DATE_GET_MINUTE(self));
	}
	return PyString_FromString(buffer);
}

static PyObject *
datetime_str(PyDateTime_DateTime *self)
{
	return PyObject_CallMethod((PyObject *)self, "isoformat", "(s)", " ");
}

static PyObject *
datetime_isoformat(PyDateTime_DateTime *self,
                   PyObject *args, PyObject *kw)
{
	char sep = 'T';
	static char *keywords[] = {"sep", NULL};
	char buffer[100];
	char *cp;

	if (!PyArg_ParseTupleAndKeywords(args, kw, "|c:isoformat", keywords,
					 &sep))
		return NULL;
	cp = isoformat_date((PyDateTime_Date *)self, buffer, sizeof(buffer));
	assert(cp != NULL);
	*cp++ = sep;
	isoformat_time(self, cp, sizeof(buffer) - (cp - buffer));
	return PyString_FromString(buffer);
}

static PyObject *
datetime_ctime(PyDateTime_DateTime *self)
{
	return format_ctime((PyDateTime_Date *)self,
			    DATE_GET_HOUR(self),
			    DATE_GET_MINUTE(self),
			    DATE_GET_SECOND(self));
}

/* Miscellaneous methods. */

/* This is more natural as a tp_compare, but doesn't work then:  for whatever
 * reason, Python's try_3way_compare ignores tp_compare unless
 * PyInstance_Check returns true, but these aren't old-style classes.
 * Note that this routine handles all comparisons for datetime and datetimetz.
 */
static PyObject *
datetime_richcompare(PyDateTime_DateTime *self, PyObject *other, int op)
{
	int diff;
	naivety n1, n2;
	int offset1, offset2;

	if (! PyDateTime_Check(other)) {
		/* Stop this from falling back to address comparison. */
		PyErr_Format(PyExc_TypeError,
			     "can't compare '%s' to '%s'",
			     self->ob_type->tp_name,
			     other->ob_type->tp_name);
		return NULL;
	}
	n1 = classify_utcoffset((PyObject *)self, &offset1);
	assert(n1 != OFFSET_UNKNOWN);
	if (n1 == OFFSET_ERROR)
		return NULL;

	n2 = classify_utcoffset(other, &offset2);
	assert(n2 != OFFSET_UNKNOWN);
	if (n2 == OFFSET_ERROR)
		return NULL;

	/* If they're both naive, or both aware and have the same offsets,
	 * we get off cheap.  Note that if they're both naive, offset1 ==
	 * offset2 == 0 at this point.
	 */
	if (n1 == n2 && offset1 == offset2) {
		diff = memcmp(self->data, ((PyDateTime_DateTime *)other)->data,
			      _PyDateTime_DATETIME_DATASIZE);
		return diff_to_bool(diff, op);
	}

	if (n1 == OFFSET_AWARE && n2 == OFFSET_AWARE) {
		/* We want the sign of
		 *     (self - offset1 minutes) - (other - offset2 minutes) =
		 *     (self - other) + (offset2 - offset1) minutes.
		 */
		PyDateTime_Delta *delta;
		int days, seconds, us;

		assert(offset1 != offset2);	/* else last "if" handled it */
		delta = (PyDateTime_Delta *)sub_datetime_datetime(self,
						(PyDateTime_DateTime *)other);
		if (delta == NULL)
			return NULL;
		days = delta->days;
		seconds = delta->seconds + (offset2 - offset1) * 60;
		us = delta->microseconds;
		Py_DECREF(delta);
		normalize_d_s_us(&days, &seconds, &us);
		diff = days;
		if (diff == 0)
			diff = seconds | us;
		return diff_to_bool(diff, op);
	}

	assert(n1 != n2);
	PyErr_SetString(PyExc_TypeError,
			"can't compare offset-naive and "
			"offset-aware datetimes");
	return NULL;
}

static PyObject *datetime_getstate(PyDateTime_DateTime *self);

static long
datetime_hash(PyDateTime_DateTime *self)
{
	if (self->hashcode == -1) {
		naivety n;
		int offset;
		PyObject *temp;

		n = classify_utcoffset((PyObject *)self, &offset);
		assert(n != OFFSET_UNKNOWN);
		if (n == OFFSET_ERROR)
			return -1;

		/* Reduce this to a hash of another object. */
		if (n == OFFSET_NAIVE)
			temp = datetime_getstate(self);
		else {
			int days;
			int seconds;

			assert(n == OFFSET_AWARE);
			assert(PyDateTimeTZ_Check(self));
			days = ymd_to_ord(GET_YEAR(self),
					  GET_MONTH(self),
					  GET_DAY(self));
			seconds = DATE_GET_HOUR(self) * 3600 +
				  (DATE_GET_MINUTE(self) - offset) * 60 +
				  DATE_GET_SECOND(self);
			temp = new_delta(days,
					 seconds,
					 DATE_GET_MICROSECOND(self),
					 1);
		}
		if (temp != NULL) {
			self->hashcode = PyObject_Hash(temp);
			Py_DECREF(temp);
		}
	}
	return self->hashcode;
}

static PyObject *
datetime_timetuple(PyDateTime_DateTime *self)
{
	return build_struct_time(GET_YEAR(self),
				 GET_MONTH(self),
				 GET_DAY(self),
				 DATE_GET_HOUR(self),
				 DATE_GET_MINUTE(self),
				 DATE_GET_SECOND(self),
				 -1);
}

static PyObject *
datetime_getdate(PyDateTime_DateTime *self)
{
	return new_date(GET_YEAR(self),
			GET_MONTH(self),
			GET_DAY(self));
}

static PyObject *
datetime_gettime(PyDateTime_DateTime *self)
{
	return new_time(DATE_GET_HOUR(self),
			DATE_GET_MINUTE(self),
			DATE_GET_SECOND(self),
			DATE_GET_MICROSECOND(self));
}

/* Pickle support.  Quite a maze! */

static PyObject *
datetime_getstate(PyDateTime_DateTime *self)
{
	return PyString_FromStringAndSize(self->data,
					  _PyDateTime_DATETIME_DATASIZE);
}

static PyObject *
datetime_setstate(PyDateTime_DateTime *self, PyObject *state)
{
	const int len = PyString_Size(state);
	unsigned char *pdata = (unsigned char*)PyString_AsString(state);

	if (! PyString_Check(state) ||
	    len != _PyDateTime_DATETIME_DATASIZE) {
		PyErr_SetString(PyExc_TypeError,
				"bad argument to datetime.__setstate__");
		return NULL;
	}
	memcpy(self->data, pdata, _PyDateTime_DATETIME_DATASIZE);
	self->hashcode = -1;

	Py_INCREF(Py_None);
	return Py_None;
}

/* XXX This seems a ridiculously inefficient way to pickle a short string. */
static PyObject *
datetime_pickler(PyObject *module, PyDateTime_DateTime *datetime)
{
	PyObject *state;
	PyObject *result = NULL;

	if (! PyDateTime_CheckExact(datetime)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to datetime pickler: %s",
			     datetime->ob_type->tp_name);
		return NULL;
	}
	state = datetime_getstate(datetime);
	if (state) {
		result = Py_BuildValue("O(O)",
				       datetime_unpickler_object,
				       state);
		Py_DECREF(state);
	}
	return result;
}

static PyObject *
datetime_unpickler(PyObject *module, PyObject *arg)
{
	PyDateTime_DateTime *self;

	if (! PyString_CheckExact(arg)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to datetime unpickler: %s",
			     arg->ob_type->tp_name);
		return NULL;
	}
	self = PyObject_New(PyDateTime_DateTime, &PyDateTime_DateTimeType);
	if (self != NULL) {
		PyObject *res = datetime_setstate(self, arg);
		if (res == NULL) {
			Py_DECREF(self);
			return NULL;
		}
		Py_DECREF(res);
	}
	return (PyObject *)self;
}

static PyMethodDef datetime_methods[] = {
	/* Class methods: */
	{"now",         (PyCFunction)datetime_now,
	 METH_NOARGS | METH_CLASS,
	 PyDoc_STR("Return a new datetime representing local day and time.")},

	{"utcnow",         (PyCFunction)datetime_utcnow,
	 METH_NOARGS | METH_CLASS,
	 PyDoc_STR("Return a new datetime representing UTC day and time.")},

	{"fromtimestamp", (PyCFunction)datetime_fromtimestamp,
	 METH_VARARGS | METH_CLASS,
	 PyDoc_STR("timestamp -> local datetime from a POSIX timestamp "
	 	   "(like time.time()).")},

	{"utcfromtimestamp", (PyCFunction)datetime_utcfromtimestamp,
	 METH_VARARGS | METH_CLASS,
	 PyDoc_STR("timestamp -> UTC datetime from a POSIX timestamp "
	 	   "(like time.time()).")},

	{"combine", (PyCFunction)datetime_combine,
	 METH_VARARGS | METH_KEYWORDS | METH_CLASS,
	 PyDoc_STR("date, time -> datetime with same date and time fields")},

	/* Instance methods: */
	{"timetuple",   (PyCFunction)datetime_timetuple, METH_NOARGS,
         PyDoc_STR("Return time tuple, compatible with time.localtime().")},

	{"date",   (PyCFunction)datetime_getdate, METH_NOARGS,
         PyDoc_STR("Return date object with same year, month and day.")},

	{"time",   (PyCFunction)datetime_gettime, METH_NOARGS,
         PyDoc_STR("Return time object with same hour, minute, second and "
         	   "microsecond.")},

	{"ctime",       (PyCFunction)datetime_ctime,	METH_NOARGS,
	 PyDoc_STR("Return ctime() style string.")},

	{"isoformat",   (PyCFunction)datetime_isoformat, METH_KEYWORDS,
	 PyDoc_STR("[sep] -> string in ISO 8601 format, "
	 	   "YYYY-MM-DDTHH:MM:SS[.mmmmmm].\n\n"
	 	   "sep is used to separate the year from the time, and "
	 	   "defaults\n"
	 	   "to 'T'.")},

	{"__setstate__", (PyCFunction)datetime_setstate, METH_O,
	 PyDoc_STR("__setstate__(state)")},

	{"__getstate__", (PyCFunction)datetime_getstate, METH_NOARGS,
	 PyDoc_STR("__getstate__() -> state")},
	{NULL,	NULL}
};

static char datetime_doc[] =
PyDoc_STR("Basic date/time type.");

static PyNumberMethods datetime_as_number = {
	datetime_add,				/* nb_add */
	datetime_subtract,			/* nb_subtract */
	0,					/* nb_multiply */
	0,					/* nb_divide */
	0,					/* nb_remainder */
	0,					/* nb_divmod */
	0,					/* nb_power */
	0,					/* nb_negative */
	0,					/* nb_positive */
	0,					/* nb_absolute */
	0,					/* nb_nonzero */
};

statichere PyTypeObject PyDateTime_DateTimeType = {
	PyObject_HEAD_INIT(NULL)
	0,					/* ob_size */
	"datetime.datetime",			/* tp_name */
	sizeof(PyDateTime_DateTime),		/* tp_basicsize */
	0,					/* tp_itemsize */
	(destructor)PyObject_Del,		/* tp_dealloc */
	0,					/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	(reprfunc)datetime_repr,		/* tp_repr */
	&datetime_as_number,			/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	(hashfunc)datetime_hash,		/* tp_hash */
	0,              			/* tp_call */
	(reprfunc)datetime_str,			/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
        Py_TPFLAGS_BASETYPE,			/* tp_flags */
	datetime_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	(richcmpfunc)datetime_richcompare,	/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	datetime_methods,			/* tp_methods */
	0,					/* tp_members */
	datetime_getset,			/* tp_getset */
	&PyDateTime_DateType,			/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	datetime_new,				/* tp_new */
	_PyObject_Del,				/* tp_free */
};

/*
 * PyDateTime_Time implementation.
 */

/* Accessor properties. */

static PyObject *
time_hour(PyDateTime_Time *self, void *unused)
{
	return PyInt_FromLong(TIME_GET_HOUR(self));
}

static PyObject *
time_minute(PyDateTime_Time *self, void *unused)
{
	return PyInt_FromLong(TIME_GET_MINUTE(self));
}

static PyObject *
py_time_second(PyDateTime_Time *self, void *unused)
{
	return PyInt_FromLong(TIME_GET_SECOND(self));
}

static PyObject *
time_microsecond(PyDateTime_Time *self, void *unused)
{
	return PyInt_FromLong(TIME_GET_MICROSECOND(self));
}

static PyGetSetDef time_getset[] = {
	{"hour",        (getter)time_hour},
	{"minute",      (getter)time_minute},
	{"second",      (getter)py_time_second},
	{"microsecond", (getter)time_microsecond},
	{NULL}
};

/* Constructors. */

static PyObject *
time_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	int hour = 0;
	int minute = 0;
	int second = 0;
	int usecond = 0;

	static char *keywords[] = {
		"hour", "minute", "second", "microsecond", NULL
	};

	if (PyArg_ParseTupleAndKeywords(args, kw, "|iiii", keywords,
					&hour, &minute, &second, &usecond)) {
		if (check_time_args(hour, minute, second, usecond) < 0)
			return NULL;
		self = new_time(hour, minute, second, usecond);
	}
	return self;
}

/* Various ways to turn a time into a string. */

static PyObject *
time_repr(PyDateTime_Time *self)
{
	char buffer[100];
	char *typename = self->ob_type->tp_name;
	int h = TIME_GET_HOUR(self);
	int m = TIME_GET_MINUTE(self);
	int s = TIME_GET_SECOND(self);
	int us = TIME_GET_MICROSECOND(self);

	if (us)
		PyOS_snprintf(buffer, sizeof(buffer),
			      "%s(%d, %d, %d, %d)", typename, h, m, s, us);
	else if (s)
		PyOS_snprintf(buffer, sizeof(buffer),
			      "%s(%d, %d, %d)", typename, h, m, s);
	else
		PyOS_snprintf(buffer, sizeof(buffer),
			      "%s(%d, %d)", typename, h, m);
	return PyString_FromString(buffer);
}

static PyObject *
time_str(PyDateTime_Time *self)
{
	return PyObject_CallMethod((PyObject *)self, "isoformat", "()");
}

static PyObject *
time_isoformat(PyDateTime_Time *self)
{
	char buffer[100];
	/* Reuse the time format code from the datetime type. */
	PyDateTime_DateTime datetime;
	PyDateTime_DateTime *pdatetime = &datetime;

	/* Copy over just the time bytes. */
	memcpy(pdatetime->data + _PyDateTime_DATE_DATASIZE,
	       self->data,
	       _PyDateTime_TIME_DATASIZE);

	isoformat_time(pdatetime, buffer, sizeof(buffer));
	return PyString_FromString(buffer);
}

static PyObject *
time_strftime(PyDateTime_Time *self, PyObject *args, PyObject *kw)
{
	PyObject *result;
	PyObject *format;
	PyObject *tuple;
	static char *keywords[] = {"format", NULL};

	if (! PyArg_ParseTupleAndKeywords(args, kw, "O!:strftime", keywords,
					  &PyString_Type, &format))
		return NULL;

	/* Python's strftime does insane things with the year part of the
	 * timetuple.  The year is forced to (the otherwise nonsensical)
	 * 1900 to worm around that.
	 */
	tuple = Py_BuildValue("iiiiiiiii",
		              1900, 0, 0, /* year, month, day */
			      TIME_GET_HOUR(self),
			      TIME_GET_MINUTE(self),
			      TIME_GET_SECOND(self),
			      0, 0, -1); /* weekday, daynum, dst */
	if (tuple == NULL)
		return NULL;
	assert(PyTuple_Size(tuple) == 9);
	result = wrap_strftime((PyObject *)self, format, tuple);
	Py_DECREF(tuple);
	return result;
}

/* Miscellaneous methods. */

/* This is more natural as a tp_compare, but doesn't work then:  for whatever
 * reason, Python's try_3way_compare ignores tp_compare unless
 * PyInstance_Check returns true, but these aren't old-style classes.
 * Note that this routine handles all comparisons for time and timetz.
 */
static PyObject *
time_richcompare(PyDateTime_Time *self, PyObject *other, int op)
{
	int diff;
	naivety n1, n2;
	int offset1, offset2;

	if (! PyTime_Check(other)) {
		/* Stop this from falling back to address comparison. */
		PyErr_Format(PyExc_TypeError,
			     "can't compare '%s' to '%s'",
			     self->ob_type->tp_name,
			     other->ob_type->tp_name);
		return NULL;
	}
	n1 = classify_utcoffset((PyObject *)self, &offset1);
	assert(n1 != OFFSET_UNKNOWN);
	if (n1 == OFFSET_ERROR)
		return NULL;

	n2 = classify_utcoffset(other, &offset2);
	assert(n2 != OFFSET_UNKNOWN);
	if (n2 == OFFSET_ERROR)
		return NULL;

	/* If they're both naive, or both aware and have the same offsets,
	 * we get off cheap.  Note that if they're both naive, offset1 ==
	 * offset2 == 0 at this point.
	 */
	if (n1 == n2 && offset1 == offset2) {
		diff = memcmp(self->data, ((PyDateTime_Time *)other)->data,
			      _PyDateTime_TIME_DATASIZE);
		return diff_to_bool(diff, op);
	}

	if (n1 == OFFSET_AWARE && n2 == OFFSET_AWARE) {
		assert(offset1 != offset2);	/* else last "if" handled it */
		/* Convert everything except microseconds to seconds.  These
		 * can't overflow (no more than the # of seconds in 2 days).
		 */
		offset1 = TIME_GET_HOUR(self) * 3600 +
			  (TIME_GET_MINUTE(self) - offset1) * 60 +
			  TIME_GET_SECOND(self);
		offset2 = TIME_GET_HOUR(other) * 3600 +
			  (TIME_GET_MINUTE(other) - offset2) * 60 +
			  TIME_GET_SECOND(other);
		diff = offset1 - offset2;
		if (diff == 0)
			diff = TIME_GET_MICROSECOND(self) -
			       TIME_GET_MICROSECOND(other);
		return diff_to_bool(diff, op);
	}

	assert(n1 != n2);
	PyErr_SetString(PyExc_TypeError,
			"can't compare offset-naive and "
			"offset-aware times");
	return NULL;
}

static PyObject *time_getstate(PyDateTime_Time *self);

static long
time_hash(PyDateTime_Time *self)
{
	if (self->hashcode == -1) {
		naivety n;
		int offset;
		PyObject *temp;

		n = classify_utcoffset((PyObject *)self, &offset);
		assert(n != OFFSET_UNKNOWN);
		if (n == OFFSET_ERROR)
			return -1;

		/* Reduce this to a hash of another object. */
		if (offset == 0)
			temp = time_getstate(self);
		else {
			int hour;
			int minute;

			assert(n == OFFSET_AWARE);
			assert(PyTimeTZ_Check(self));
			hour = divmod(TIME_GET_HOUR(self) * 60 +
					TIME_GET_MINUTE(self) - offset,
				      60,
				      &minute);
			if (0 <= hour && hour < 24)
				temp = new_time(hour, minute,
						TIME_GET_SECOND(self),
						TIME_GET_MICROSECOND(self));
			else
				temp = Py_BuildValue("iiii",
					   hour, minute,
					   TIME_GET_SECOND(self),
					   TIME_GET_MICROSECOND(self));
		}
		if (temp != NULL) {
			self->hashcode = PyObject_Hash(temp);
			Py_DECREF(temp);
		}
	}
	return self->hashcode;
}

static int
time_nonzero(PyDateTime_Time *self)
{
	return TIME_GET_HOUR(self) ||
	       TIME_GET_MINUTE(self) ||
	       TIME_GET_SECOND(self) ||
	       TIME_GET_MICROSECOND(self);
}

/* Pickle support.  Quite a maze! */

static PyObject *
time_getstate(PyDateTime_Time *self)
{
	return PyString_FromStringAndSize(self->data,
					  _PyDateTime_TIME_DATASIZE);
}

static PyObject *
time_setstate(PyDateTime_Time *self, PyObject *state)
{
	const int len = PyString_Size(state);
	unsigned char *pdata = (unsigned char*)PyString_AsString(state);

	if (! PyString_Check(state) ||
	    len != _PyDateTime_TIME_DATASIZE) {
		PyErr_SetString(PyExc_TypeError,
				"bad argument to time.__setstate__");
		return NULL;
	}
	memcpy(self->data, pdata, _PyDateTime_TIME_DATASIZE);
	self->hashcode = -1;

	Py_INCREF(Py_None);
	return Py_None;
}

/* XXX This seems a ridiculously inefficient way to pickle a short string. */
static PyObject *
time_pickler(PyObject *module, PyDateTime_Time *time)
{
	PyObject *state;
	PyObject *result = NULL;

	if (! PyTime_CheckExact(time)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to time pickler: %s",
			     time->ob_type->tp_name);
		return NULL;
	}
	state = time_getstate(time);
	if (state) {
		result = Py_BuildValue("O(O)",
				       time_unpickler_object,
				       state);
		Py_DECREF(state);
	}
	return result;
}

static PyObject *
time_unpickler(PyObject *module, PyObject *arg)
{
	PyDateTime_Time *self;

	if (! PyString_CheckExact(arg)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to time unpickler: %s",
			     arg->ob_type->tp_name);
		return NULL;
	}
	self = PyObject_New(PyDateTime_Time, &PyDateTime_TimeType);
	if (self != NULL) {
		PyObject *res = time_setstate(self, arg);
		if (res == NULL) {
			Py_DECREF(self);
			return NULL;
		}
		Py_DECREF(res);
	}
	return (PyObject *)self;
}

static PyMethodDef time_methods[] = {
	{"isoformat",   (PyCFunction)time_isoformat,	METH_KEYWORDS,
	 PyDoc_STR("Return string in ISO 8601 format, HH:MM:SS[.mmmmmm].")},

	{"strftime",   	(PyCFunction)time_strftime,	METH_KEYWORDS,
	 PyDoc_STR("format -> strftime() style string.")},

	{"__setstate__", (PyCFunction)time_setstate,	METH_O,
	 PyDoc_STR("__setstate__(state)")},

	{"__getstate__", (PyCFunction)time_getstate,	METH_NOARGS,
	 PyDoc_STR("__getstate__() -> state")},
	{NULL,	NULL}
};

static char time_doc[] =
PyDoc_STR("Basic time type.");

static PyNumberMethods time_as_number = {
	0,					/* nb_add */
	0,					/* nb_subtract */
	0,					/* nb_multiply */
	0,					/* nb_divide */
	0,					/* nb_remainder */
	0,					/* nb_divmod */
	0,					/* nb_power */
	0,					/* nb_negative */
	0,					/* nb_positive */
	0,					/* nb_absolute */
	(inquiry)time_nonzero,			/* nb_nonzero */
};

statichere PyTypeObject PyDateTime_TimeType = {
	PyObject_HEAD_INIT(NULL)
	0,					/* ob_size */
	"datetime.time",			/* tp_name */
	sizeof(PyDateTime_Time),		/* tp_basicsize */
	0,					/* tp_itemsize */
	(destructor)PyObject_Del,		/* tp_dealloc */
	0,					/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	(reprfunc)time_repr,			/* tp_repr */
	&time_as_number,			/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	(hashfunc)time_hash,			/* tp_hash */
	0,              			/* tp_call */
	(reprfunc)time_str,			/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
        Py_TPFLAGS_BASETYPE,			/* tp_flags */
	time_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	(richcmpfunc)time_richcompare,		/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	time_methods,				/* tp_methods */
	0,					/* tp_members */
	time_getset,				/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	time_new,				/* tp_new */
	_PyObject_Del,				/* tp_free */
};

/*
 * PyDateTime_TZInfo implementation.
 */

/* This is a pure abstract base class, so doesn't do anything beyond
 * raising NotImplemented exceptions.  Real tzinfo classes need
 * to derive from this.  This is mostly for clarity, and for efficiency in
 * datetimetz and timetz constructors (their tzinfo arguments need to
 * be subclasses of this tzinfo class, which is easy and quick to check).
 *
 * Note:  For reasons having to do with pickling of subclasses, we have
 * to allow tzinfo objects to be instantiated.  This wasn't an issue
 * in the Python implementation (__init__() could raise NotImplementedError
 * there without ill effect), but doing so in the C implementation hit a
 * brick wall.
 */

static PyObject *
tzinfo_nogo(const char* methodname)
{
	PyErr_Format(PyExc_NotImplementedError,
		     "a tzinfo subclass must implement %s()",
		     methodname);
	return NULL;
}

/* Methods.  A subclass must implement these. */

static PyObject*
tzinfo_tzname(PyDateTime_TZInfo *self, PyObject *dt)
{
	return tzinfo_nogo("tzname");
}

static PyObject*
tzinfo_utcoffset(PyDateTime_TZInfo *self, PyObject *dt)
{
	return tzinfo_nogo("utcoffset");
}

static PyObject*
tzinfo_dst(PyDateTime_TZInfo *self, PyObject *dt)
{
	return tzinfo_nogo("dst");
}

/*
 * Pickle support.  This is solely so that tzinfo subclasses can use
 * pickling -- tzinfo itself is supposed to be uninstantiable.  The
 * pickler and unpickler functions are given module-level private
 * names, and registered with copy_reg, by the module init function.
 */

static PyObject*
tzinfo_pickler(PyDateTime_TZInfo *self) {
	return Py_BuildValue("O()", tzinfo_unpickler_object);
}

static PyObject*
tzinfo_unpickler(PyObject * unused) {
 	return PyType_GenericNew(&PyDateTime_TZInfoType, NULL, NULL);
}


static PyMethodDef tzinfo_methods[] = {
	{"tzname",	(PyCFunction)tzinfo_tzname,		METH_O,
	 PyDoc_STR("datetime -> string name of time zone.")},

	{"utcoffset",	(PyCFunction)tzinfo_utcoffset,		METH_O,
	 PyDoc_STR("datetime -> minutes east of UTC (negative for "
	 	   "west of UTC).")},

	{"dst",		(PyCFunction)tzinfo_dst,		METH_O,
	 PyDoc_STR("datetime -> DST offset in minutes east of UTC.")},

	{NULL, NULL}
};

static char tzinfo_doc[] =
PyDoc_STR("Abstract base class for time zone info objects.");

 statichere PyTypeObject PyDateTime_TZInfoType = {
	PyObject_HEAD_INIT(NULL)
	0,					/* ob_size */
	"datetime.tzinfo",			/* tp_name */
	sizeof(PyDateTime_TZInfo),		/* tp_basicsize */
	0,					/* tp_itemsize */
	0,					/* tp_dealloc */
	0,					/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	0,					/* tp_repr */
	0,					/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	0,					/* tp_hash */
	0,              			/* tp_call */
	0,					/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
        Py_TPFLAGS_BASETYPE,			/* tp_flags */
	tzinfo_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	tzinfo_methods,				/* tp_methods */
	0,					/* tp_members */
	0,					/* tp_getset */
	0,					/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	PyType_GenericNew,			/* tp_new */
	0,					/* tp_free */
};

/*
 * PyDateTime_TimeTZ implementation.
 */

/* Accessor properties.  Properties for hour, minute, second and microsecond
 * are inherited from time.
 */

static PyObject *
timetz_tzinfo(PyDateTime_TimeTZ *self, void *unused)
{
	Py_INCREF(self->tzinfo);
	return self->tzinfo;
}

static PyGetSetDef timetz_getset[] = {
	{"tzinfo", (getter)timetz_tzinfo},
	{NULL}
};

/*
 * Constructors.
 */

static PyObject *
timetz_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	int hour = 0;
	int minute = 0;
	int second = 0;
	int usecond = 0;
	PyObject *tzinfo = Py_None;

	static char *keywords[] = {
		"hour", "minute", "second", "microsecond", "tzinfo", NULL
	};

	if (PyArg_ParseTupleAndKeywords(args, kw, "|iiiiO", keywords,
					&hour, &minute, &second, &usecond,
					&tzinfo)) {
		if (check_time_args(hour, minute, second, usecond) < 0)
			return NULL;
		if (check_tzinfo_subclass(tzinfo) < 0)
			return NULL;
		self = new_timetz(hour, minute, second, usecond, tzinfo);
	}
	return self;
}

/*
 * Destructor.
 */

static void
timetz_dealloc(PyDateTime_TimeTZ *self)
{
	Py_XDECREF(self->tzinfo);
	self->ob_type->tp_free((PyObject *)self);
}

/*
 * Indirect access to tzinfo methods.
 */

/* These are all METH_NOARGS, so don't need to check the arglist. */
static PyObject *
timetz_utcoffset(PyDateTime_TimeTZ *self, PyObject *unused) {
	return offset_as_timedelta((PyObject *)self, self->tzinfo,
				   "utcoffset");
}

static PyObject *
timetz_dst(PyDateTime_TimeTZ *self, PyObject *unused) {
	return offset_as_timedelta((PyObject *)self, self->tzinfo, "dst");
}

static PyObject *
timetz_tzname(PyDateTime_TimeTZ *self, PyObject *unused) {
	return call_tzname((PyObject *)self, self->tzinfo);
}

/*
 * Various ways to turn a timetz into a string.
 */

static PyObject *
timetz_repr(PyDateTime_TimeTZ *self)
{
	PyObject *baserepr = time_repr((PyDateTime_Time *)self);

	if (baserepr == NULL)
		return NULL;
	return append_keyword_tzinfo(baserepr, self->tzinfo);
}

/* Note:  tp_str is inherited from time. */

static PyObject *
timetz_isoformat(PyDateTime_TimeTZ *self)
{
	char buf[100];
	PyObject *result = time_isoformat((PyDateTime_Time *)self);

	if (result == NULL || self->tzinfo == Py_None)
		return result;

	/* We need to append the UTC offset. */
	if (format_utcoffset(buf, sizeof(buf), ":", self->tzinfo,
			     (PyObject *)self) < 0) {
		Py_DECREF(result);
		return NULL;
	}
	PyString_ConcatAndDel(&result, PyString_FromString(buf));
	return result;
}

/* Note:  strftime() is inherited from time. */

/*
 * Miscellaneous methods.
 */

/* Note:  tp_richcompare and tp_hash are inherited from time. */

static int
timetz_nonzero(PyDateTime_TimeTZ *self)
{
	int offset;
	int none;

	if (TIME_GET_SECOND(self) || TIME_GET_MICROSECOND(self)) {
		/* Since utcoffset is in whole minutes, nothing can
		 * alter the conclusion that this is nonzero.
		 */
		return 1;
	}
	offset = 0;
	if (self->tzinfo != Py_None) {
		offset = call_utcoffset(self->tzinfo, (PyObject *)self, &none);
		if (offset == -1 && PyErr_Occurred())
			return -1;
	}
	return (TIME_GET_MINUTE(self) - offset + TIME_GET_HOUR(self)*60) != 0;
}

/*
 * Pickle support.  Quite a maze!
 */

/* Let basestate be the state string returned by time_getstate.
 * If tzinfo is None, this returns (basestate,), else (basestate, tzinfo).
 * So it's a tuple in any (non-error) case.
 */
static PyObject *
timetz_getstate(PyDateTime_TimeTZ *self)
{
	PyObject *basestate;
	PyObject *result = NULL;

	basestate = time_getstate((PyDateTime_Time *)self);
	if (basestate != NULL) {
		if (self->tzinfo == Py_None)
			result = Py_BuildValue("(O)", basestate);
		else
			result = Py_BuildValue("OO", basestate, self->tzinfo);
		Py_DECREF(basestate);
	}
	return result;
}

static PyObject *
timetz_setstate(PyDateTime_TimeTZ *self, PyObject *state)
{
	PyObject *temp;
	PyObject *basestate;
	PyObject *tzinfo = Py_None;

	if (! PyArg_ParseTuple(state, "O!|O:__setstate__",
			       &PyString_Type, &basestate,
			       &tzinfo))
		return NULL;
	temp = time_setstate((PyDateTime_Time *)self, basestate);
	if (temp == NULL)
		return NULL;
	Py_DECREF(temp);

	Py_INCREF(tzinfo);
	Py_XDECREF(self->tzinfo);
	self->tzinfo = tzinfo;

	Py_INCREF(Py_None);
	return Py_None;
}

static PyObject *
timetz_pickler(PyObject *module, PyDateTime_TimeTZ *timetz)
{
	PyObject *state;
	PyObject *result = NULL;

	if (! PyTimeTZ_CheckExact(timetz)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to timetz pickler: %s",
			     timetz->ob_type->tp_name);
		return NULL;
	}
	state = timetz_getstate(timetz);
	if (state) {
		result = Py_BuildValue("O(O)",
				       timetz_unpickler_object,
				       state);
		Py_DECREF(state);
	}
	return result;
}

static PyObject *
timetz_unpickler(PyObject *module, PyObject *arg)
{
	PyDateTime_TimeTZ *self;

	self = PyObject_New(PyDateTime_TimeTZ, &PyDateTime_TimeTZType);
	if (self != NULL) {
		PyObject *res;

		self->tzinfo = NULL;
		res = timetz_setstate(self, arg);
		if (res == NULL) {
			Py_DECREF(self);
			return NULL;
		}
		Py_DECREF(res);
	}
	return (PyObject *)self;
}

static PyMethodDef timetz_methods[] = {
	{"isoformat",   (PyCFunction)timetz_isoformat,	METH_KEYWORDS,
	 PyDoc_STR("Return string in ISO 8601 format, HH:MM:SS[.mmmmmm]"
	 	   "[+HH:MM].")},

	{"utcoffset",	(PyCFunction)timetz_utcoffset,	METH_NOARGS,
	 PyDoc_STR("Return self.tzinfo.utcoffset(self).")},

	{"tzname",	(PyCFunction)timetz_tzname,	METH_NOARGS,
	 PyDoc_STR("Return self.tzinfo.tzname(self).")},

	{"dst",		(PyCFunction)timetz_dst,	METH_NOARGS,
	 PyDoc_STR("Return self.tzinfo.dst(self).")},

	{"__setstate__", (PyCFunction)timetz_setstate,	METH_O,
	 PyDoc_STR("__setstate__(state)")},

	{"__getstate__", (PyCFunction)timetz_getstate,	METH_NOARGS,
	 PyDoc_STR("__getstate__() -> state")},
	{NULL,	NULL}

};

static char timetz_doc[] =
PyDoc_STR("Time type.");

static PyNumberMethods timetz_as_number = {
	0,					/* nb_add */
	0,					/* nb_subtract */
	0,					/* nb_multiply */
	0,					/* nb_divide */
	0,					/* nb_remainder */
	0,					/* nb_divmod */
	0,					/* nb_power */
	0,					/* nb_negative */
	0,					/* nb_positive */
	0,					/* nb_absolute */
	(inquiry)timetz_nonzero,		/* nb_nonzero */
};

statichere PyTypeObject PyDateTime_TimeTZType = {
	PyObject_HEAD_INIT(NULL)
	0,					/* ob_size */
	"datetime.timetz",			/* tp_name */
	sizeof(PyDateTime_TimeTZ),		/* tp_basicsize */
	0,					/* tp_itemsize */
	(destructor)timetz_dealloc,		/* tp_dealloc */
	0,					/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	(reprfunc)timetz_repr,			/* tp_repr */
	&timetz_as_number,			/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	0,					/* tp_hash */
	0,              			/* tp_call */
	0,					/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
        Py_TPFLAGS_BASETYPE,			/* tp_flags */
	timetz_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	timetz_methods,				/* tp_methods */
	0,					/* tp_members */
	timetz_getset,				/* tp_getset */
	&PyDateTime_TimeType,			/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	timetz_new,				/* tp_new */
	_PyObject_Del,				/* tp_free */
};

/*
 * PyDateTime_DateTimeTZ implementation.
 */

/* Accessor properties.  Properties for day, month, year, hour, minute,
 * second and microsecond are inherited from datetime.
 */

static PyObject *
datetimetz_tzinfo(PyDateTime_DateTimeTZ *self, void *unused)
{
	Py_INCREF(self->tzinfo);
	return self->tzinfo;
}

static PyGetSetDef datetimetz_getset[] = {
	{"tzinfo", (getter)datetimetz_tzinfo},
	{NULL}
};

/*
 * Constructors.
 * These are like the datetime methods of the same names, but allow an
 * optional tzinfo argument.
 */

/* Internal helper.
 * self is a datetimetz.  Replace its tzinfo member.
 */
void
replace_tzinfo(PyObject *self, PyObject *newtzinfo)
{
	assert(self != NULL);
	assert(newtzinfo != NULL);
	assert(PyDateTimeTZ_Check(self));
	Py_INCREF(newtzinfo);
	Py_DECREF(((PyDateTime_DateTimeTZ *)self)->tzinfo);
	((PyDateTime_DateTimeTZ *)self)->tzinfo = newtzinfo;
}

static PyObject *
datetimetz_new(PyTypeObject *type, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	int year;
	int month;
	int day;
	int hour = 0;
	int minute = 0;
	int second = 0;
	int usecond = 0;
	PyObject *tzinfo = Py_None;

	static char *keywords[] = {
		"year", "month", "day", "hour", "minute", "second",
		"microsecond", "tzinfo", NULL
	};

	if (PyArg_ParseTupleAndKeywords(args, kw, "iii|iiiiO", keywords,
					&year, &month, &day, &hour, &minute,
					&second, &usecond, &tzinfo)) {
		if (check_date_args(year, month, day) < 0)
			return NULL;
		if (check_time_args(hour, minute, second, usecond) < 0)
			return NULL;
		if (check_tzinfo_subclass(tzinfo) < 0)
			return NULL;
		self = new_datetimetz(year, month, day,
				      hour, minute, second, usecond,
				      tzinfo);
	}
	return self;
}

/* Return best possible local time -- this isn't constrained by the
 * precision of a timestamp.
 */
static PyObject *
datetimetz_now(PyObject *cls, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	PyObject *tzinfo = Py_None;
	static char *keywords[] = {"tzinfo", NULL};

	if (PyArg_ParseTupleAndKeywords(args, kw, "|O:now", keywords,
					&tzinfo)) {
		if (check_tzinfo_subclass(tzinfo) < 0)
			return NULL;
		self = datetime_best_possible(cls, localtime);
		if (self != NULL)
			replace_tzinfo(self, tzinfo);
	}
	return self;
}

/* Return new local datetime from timestamp (Python timestamp -- a double). */
static PyObject *
datetimetz_fromtimestamp(PyObject *cls, PyObject *args, PyObject *kw)
{
	PyObject *self = NULL;
	double timestamp;
	PyObject *tzinfo = Py_None;
	static char *keywords[] = {"timestamp", "tzinfo", NULL};

	if (PyArg_ParseTupleAndKeywords(args, kw, "d|O:fromtimestamp",
					keywords, &timestamp, &tzinfo)) {
		if (check_tzinfo_subclass(tzinfo) < 0)
			return NULL;
		self = datetime_from_timestamp(cls, localtime, timestamp);
		if (self != NULL)
			replace_tzinfo(self, tzinfo);
	}
	return self;
}

/* Note:  utcnow() is inherited, and doesn't accept tzinfo.
 * Ditto utcfromtimestamp().  Ditto combine().
 */


/*
 * Destructor.
 */

static void
datetimetz_dealloc(PyDateTime_DateTimeTZ *self)
{
	Py_XDECREF(self->tzinfo);
	self->ob_type->tp_free((PyObject *)self);
}

/*
 * Indirect access to tzinfo methods.
 */

/* These are all METH_NOARGS, so don't need to check the arglist. */
static PyObject *
datetimetz_utcoffset(PyDateTime_DateTimeTZ *self, PyObject *unused) {
	return offset_as_timedelta((PyObject *)self, self->tzinfo,
				   "utcoffset");
}

static PyObject *
datetimetz_dst(PyDateTime_DateTimeTZ *self, PyObject *unused) {
	return offset_as_timedelta((PyObject *)self, self->tzinfo, "dst");
}

static PyObject *
datetimetz_tzname(PyDateTime_DateTimeTZ *self, PyObject *unused) {
	return call_tzname((PyObject *)self, self->tzinfo);
}

/*
 * datetimetz arithmetic.
 */

/* If base is Py_NotImplemented or NULL, just return it.
 * Else base is a datetime, exactly one of {left, right} is a datetimetz,
 * and we want to create a datetimetz with the same date and time fields
 * as base, and with the tzinfo field from left or right.  Do that,
 * return it, and decref base.  This is used to transform the result of
 * a binary datetime operation (base) into a datetimetz result.
 */
static PyObject *
attach_tzinfo(PyObject *base, PyObject *left, PyObject *right)
{
	PyDateTime_DateTimeTZ *self;
	PyDateTime_DateTimeTZ *result;

	if (base == NULL || base == Py_NotImplemented)
		return base;

	assert(PyDateTime_CheckExact(base));

	if (PyDateTimeTZ_Check(left)) {
		assert(! PyDateTimeTZ_Check(right));
		self = (PyDateTime_DateTimeTZ *)left;
	}
	else {
		assert(PyDateTimeTZ_Check(right));
		self = (PyDateTime_DateTimeTZ *)right;
	}
	result = PyObject_New(PyDateTime_DateTimeTZ,
			      &PyDateTime_DateTimeTZType);
	if (result != NULL) {
		memcpy(result->data, ((PyDateTime_DateTime *)base)->data,
		       _PyDateTime_DATETIME_DATASIZE);
		Py_INCREF(self->tzinfo);
		result->tzinfo = self->tzinfo;
	}
	Py_DECREF(base);
	return (PyObject *)result;
}

static PyObject *
datetimetz_add(PyObject *left, PyObject *right)
{
	return attach_tzinfo(datetime_add(left, right), left, right);
}

static PyObject *
datetimetz_subtract(PyObject *left, PyObject *right)
{
	PyObject *result = Py_NotImplemented;

	if (PyDateTime_Check(left)) {
		/* datetime - ??? */
		if (PyDateTime_Check(right)) {
			/* datetime - datetime */
			naivety n1, n2;
			int offset1, offset2;
			PyDateTime_Delta *delta;

			n1 = classify_utcoffset(left, &offset1);
			assert(n1 != OFFSET_UNKNOWN);
			if (n1 == OFFSET_ERROR)
				return NULL;

			n2 = classify_utcoffset(right, &offset2);
			assert(n2 != OFFSET_UNKNOWN);
			if (n2 == OFFSET_ERROR)
				return NULL;

			if (n1 != n2) {
				PyErr_SetString(PyExc_TypeError,
					"can't subtract offset-naive and "
					"offset-aware datetimes");
				return NULL;
			}
			delta = (PyDateTime_Delta *)sub_datetime_datetime(
						(PyDateTime_DateTime *)left,
						(PyDateTime_DateTime *)right);
			if (delta == NULL || offset1 == offset2)
				return (PyObject *)delta;
			/* (left - offset1) - (right - offset2) =
			 * (left - right) + (offset2 - offset1)
			 */
			result = new_delta(delta->days,
					   delta->seconds +
					   	(offset2 - offset1) * 60,
					   delta->microseconds,
					   1);
			Py_DECREF(delta);
		}
		else if (PyDelta_Check(right)) {
			/* datetimetz - delta */
			result = sub_datetime_timedelta(
					(PyDateTime_DateTime *)left,
					(PyDateTime_Delta *)right);
			result = attach_tzinfo(result, left, right);
		}
	}

	if (result == Py_NotImplemented)
		Py_INCREF(result);
	return result;
}

/* Various ways to turn a datetime into a string. */

static PyObject *
datetimetz_repr(PyDateTime_DateTimeTZ *self)
{
	PyObject *baserepr = datetime_repr((PyDateTime_DateTime *)self);

	if (baserepr == NULL)
		return NULL;
	return append_keyword_tzinfo(baserepr, self->tzinfo);
}

/* Note:  tp_str is inherited from datetime. */

static PyObject *
datetimetz_isoformat(PyDateTime_DateTimeTZ *self,
		     PyObject *args, PyObject *kw)
{
	char buf[100];
	PyObject *result = datetime_isoformat((PyDateTime_DateTime *)self,
					      args, kw);

	if (result == NULL || self->tzinfo == Py_None)
		return result;

	/* We need to append the UTC offset. */
	if (format_utcoffset(buf, sizeof(buf), ":", self->tzinfo,
			     (PyObject *)self) < 0) {
		Py_DECREF(result);
		return NULL;
	}
	PyString_ConcatAndDel(&result, PyString_FromString(buf));
	return result;
}

/* Miscellaneous methods. */

/* Note:  tp_richcompare and tp_hash are inherited from datetime. */

static PyObject *
datetimetz_timetuple(PyDateTime_DateTimeTZ *self)
{
	int dstflag = -1;

	if (self->tzinfo != Py_None) {
		int none;

		dstflag = call_dst(self->tzinfo, (PyObject *)self, &none);
		if (dstflag == -1 && PyErr_Occurred())
			return NULL;

		if (none)
			dstflag = -1;
		else if (dstflag != 0)
			dstflag = 1;

	}
	return build_struct_time(GET_YEAR(self),
				 GET_MONTH(self),
				 GET_DAY(self),
				 DATE_GET_HOUR(self),
				 DATE_GET_MINUTE(self),
				 DATE_GET_SECOND(self),
				 dstflag);
}

static PyObject *
datetimetz_utctimetuple(PyDateTime_DateTimeTZ *self)
{
	int y = GET_YEAR(self);
	int m = GET_MONTH(self);
	int d = GET_DAY(self);
	int hh = DATE_GET_HOUR(self);
	int mm = DATE_GET_MINUTE(self);
	int ss = DATE_GET_SECOND(self);
	int us = 0;	/* microseconds are ignored in a timetuple */
	int offset = 0;

	if (self->tzinfo != Py_None) {
		int none;

		offset = call_utcoffset(self->tzinfo, (PyObject *)self, &none);
		if (offset == -1 && PyErr_Occurred())
			return NULL;
	}
	/* Even if offset is 0, don't call timetuple() -- tm_isdst should be
	 * 0 in a UTC timetuple regardless of what dst() says.
	 */
	if (offset) {
		/* Subtract offset minutes & normalize. */
		int stat;

		mm -= offset;
		stat = normalize_datetime(&y, &m, &d, &hh, &mm, &ss, &us);
		if (stat < 0) {
			/* At the edges, it's possible we overflowed
			 * beyond MINYEAR or MAXYEAR.
			 */
			if (PyErr_ExceptionMatches(PyExc_OverflowError))
				PyErr_Clear();
			else
				return NULL;
		}
	}
	return build_struct_time(y, m, d, hh, mm, ss, 0);
}

static PyObject *
datetimetz_gettimetz(PyDateTime_DateTimeTZ *self)
{
	return new_timetz(DATE_GET_HOUR(self),
			  DATE_GET_MINUTE(self),
			  DATE_GET_SECOND(self),
			  DATE_GET_MICROSECOND(self),
			  self->tzinfo);
}

/*
 * Pickle support.  Quite a maze!
 */

/* Let basestate be the state string returned by datetime_getstate.
 * If tzinfo is None, this returns (basestate,), else (basestate, tzinfo).
 * So it's a tuple in any (non-error) case.
 */
static PyObject *
datetimetz_getstate(PyDateTime_DateTimeTZ *self)
{
	PyObject *basestate;
	PyObject *result = NULL;

	basestate = datetime_getstate((PyDateTime_DateTime *)self);
	if (basestate != NULL) {
		if (self->tzinfo == Py_None)
			result = Py_BuildValue("(O)", basestate);
		else
			result = Py_BuildValue("OO", basestate, self->tzinfo);
		Py_DECREF(basestate);
	}
	return result;
}

static PyObject *
datetimetz_setstate(PyDateTime_DateTimeTZ *self, PyObject *state)
{
	PyObject *temp;
	PyObject *basestate;
	PyObject *tzinfo = Py_None;

	if (! PyArg_ParseTuple(state, "O!|O:__setstate__",
			       &PyString_Type, &basestate,
			       &tzinfo))
		return NULL;
	temp = datetime_setstate((PyDateTime_DateTime *)self, basestate);
	if (temp == NULL)
		return NULL;
	Py_DECREF(temp);

	Py_INCREF(tzinfo);
	Py_XDECREF(self->tzinfo);
	self->tzinfo = tzinfo;

	Py_INCREF(Py_None);
	return Py_None;
}

static PyObject *
datetimetz_pickler(PyObject *module, PyDateTime_DateTimeTZ *datetimetz)
{
	PyObject *state;
	PyObject *result = NULL;

	if (! PyDateTimeTZ_CheckExact(datetimetz)) {
		PyErr_Format(PyExc_TypeError,
			     "bad type passed to datetimetz pickler: %s",
			     datetimetz->ob_type->tp_name);
		return NULL;
	}
	state = datetimetz_getstate(datetimetz);
	if (state) {
		result = Py_BuildValue("O(O)",
				       datetimetz_unpickler_object,
				       state);
		Py_DECREF(state);
	}
	return result;
}

static PyObject *
datetimetz_unpickler(PyObject *module, PyObject *arg)
{
	PyDateTime_DateTimeTZ *self;

	self = PyObject_New(PyDateTime_DateTimeTZ, &PyDateTime_DateTimeTZType);
	if (self != NULL) {
		PyObject *res;

		self->tzinfo = NULL;
		res = datetimetz_setstate(self, arg);
		if (res == NULL) {
			Py_DECREF(self);
			return NULL;
		}
		Py_DECREF(res);
	}
	return (PyObject *)self;
}


static PyMethodDef datetimetz_methods[] = {
	/* Class methods: */
	/* Inherited: combine(), utcnow(), utcfromtimestamp() */

	{"now",         (PyCFunction)datetimetz_now,
	 METH_KEYWORDS | METH_CLASS,
	 PyDoc_STR("[tzinfo] -> new datetimetz with local day and time.")},

	{"fromtimestamp", (PyCFunction)datetimetz_fromtimestamp,
	 METH_KEYWORDS | METH_CLASS,
	 PyDoc_STR("timestamp[, tzinfo] -> local time from POSIX timestamp.")},

	/* Instance methods: */
	/* Inherited:  date(), time(), ctime(). */
	{"timetuple",   (PyCFunction)datetimetz_timetuple, METH_NOARGS,
         PyDoc_STR("Return time tuple, compatible with time.localtime().")},

	{"utctimetuple",   (PyCFunction)datetimetz_utctimetuple, METH_NOARGS,
         PyDoc_STR("Return UTC time tuple, compatible with time.localtime().")},

	{"timetz",   (PyCFunction)datetimetz_gettimetz, METH_NOARGS,
         PyDoc_STR("Return timetz object with same hour, minute, second, "
         	   "microsecond, and tzinfo.")},

	{"isoformat",   (PyCFunction)datetimetz_isoformat, METH_KEYWORDS,
	 PyDoc_STR("[sep] -> string in ISO 8601 format, "
	 	   "YYYY-MM-DDTHH:MM:SS[.mmmmmm][+HH:MM].\n\n"
	 	   "sep is used to separate the year from the time, and "
	 	   "defaults to 'T'.")},

	{"utcoffset",	(PyCFunction)datetimetz_utcoffset, METH_NOARGS,
	 PyDoc_STR("Return self.tzinfo.utcoffset(self).")},

	{"tzname",	(PyCFunction)datetimetz_tzname,	METH_NOARGS,
	 PyDoc_STR("Return self.tzinfo.tzname(self).")},

	{"dst",		(PyCFunction)datetimetz_dst, METH_NOARGS,
	 PyDoc_STR("Return self.tzinfo.dst(self).")},

	{"__setstate__", (PyCFunction)datetimetz_setstate, METH_O,
	 PyDoc_STR("__setstate__(state)")},

	{"__getstate__", (PyCFunction)datetimetz_getstate, METH_NOARGS,
	 PyDoc_STR("__getstate__() -> state")},
	{NULL,	NULL}
};

static char datetimetz_doc[] =
PyDoc_STR("date/time type.");

static PyNumberMethods datetimetz_as_number = {
	datetimetz_add,				/* nb_add */
	datetimetz_subtract,			/* nb_subtract */
	0,					/* nb_multiply */
	0,					/* nb_divide */
	0,					/* nb_remainder */
	0,					/* nb_divmod */
	0,					/* nb_power */
	0,					/* nb_negative */
	0,					/* nb_positive */
	0,					/* nb_absolute */
	0,					/* nb_nonzero */
};

statichere PyTypeObject PyDateTime_DateTimeTZType = {
	PyObject_HEAD_INIT(NULL)
	0,					/* ob_size */
	"datetime.datetimetz",			/* tp_name */
	sizeof(PyDateTime_DateTimeTZ),		/* tp_basicsize */
	0,					/* tp_itemsize */
	(destructor)datetimetz_dealloc,		/* tp_dealloc */
	0,					/* tp_print */
	0,					/* tp_getattr */
	0,					/* tp_setattr */
	0,					/* tp_compare */
	(reprfunc)datetimetz_repr,		/* tp_repr */
	&datetimetz_as_number,			/* tp_as_number */
	0,					/* tp_as_sequence */
	0,					/* tp_as_mapping */
	0,					/* tp_hash */
	0,              			/* tp_call */
	0,					/* tp_str */
	PyObject_GenericGetAttr,		/* tp_getattro */
	0,					/* tp_setattro */
	0,					/* tp_as_buffer */
	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_CHECKTYPES |
        Py_TPFLAGS_BASETYPE,			/* tp_flags */
	datetimetz_doc,				/* tp_doc */
	0,					/* tp_traverse */
	0,					/* tp_clear */
	0,					/* tp_richcompare */
	0,					/* tp_weaklistoffset */
	0,					/* tp_iter */
	0,					/* tp_iternext */
	datetimetz_methods,			/* tp_methods */
	0,					/* tp_members */
	datetimetz_getset,			/* tp_getset */
	&PyDateTime_DateTimeType,		/* tp_base */
	0,					/* tp_dict */
	0,					/* tp_descr_get */
	0,					/* tp_descr_set */
	0,					/* tp_dictoffset */
	0,					/* tp_init */
	0,					/* tp_alloc */
	datetimetz_new,				/* tp_new */
	_PyObject_Del,				/* tp_free */
};

/* ---------------------------------------------------------------------------
 * Module methods and initialization.
 */

static PyMethodDef module_methods[] = {
	/* Private functions for pickling support, registered with the
	 * copy_reg module by the module init function.
	 */
	{"_date_pickler",	(PyCFunction)date_pickler,	METH_O, NULL},
	{"_date_unpickler",	(PyCFunction)date_unpickler, 	METH_O, NULL},
	{"_datetime_pickler",	(PyCFunction)datetime_pickler,	METH_O, NULL},
	{"_datetime_unpickler",	(PyCFunction)datetime_unpickler,METH_O, NULL},
	{"_datetimetz_pickler",	(PyCFunction)datetimetz_pickler,METH_O, NULL},
	{"_datetimetz_unpickler",(PyCFunction)datetimetz_unpickler,METH_O, NULL},
	{"_time_pickler",	(PyCFunction)time_pickler,	METH_O, NULL},
	{"_time_unpickler",	(PyCFunction)time_unpickler,	METH_O, NULL},
	{"_timetz_pickler",	(PyCFunction)timetz_pickler,	METH_O, NULL},
	{"_timetz_unpickler",	(PyCFunction)timetz_unpickler,	METH_O, NULL},
	{"_tzinfo_pickler",	(PyCFunction)tzinfo_pickler,	METH_O, NULL},
	{"_tzinfo_unpickler",	(PyCFunction)tzinfo_unpickler,	METH_NOARGS,
	 NULL},
	{NULL, NULL}
};

PyMODINIT_FUNC
initdatetime(void)
{
	PyObject *m;	/* a module object */
	PyObject *d;	/* its dict */
	PyObject *x;

	/* Types that use __reduce__ for pickling need to set the following
	 * magical attr in the type dict, with a true value.
	 */
	PyObject *safepickle = PyString_FromString("__safe_for_unpickling__");
	if (safepickle == NULL)
		return;

	m = Py_InitModule3("datetime", module_methods,
			   "Fast implementation of the datetime type.");

	if (PyType_Ready(&PyDateTime_DateType) < 0)
		return;
	if (PyType_Ready(&PyDateTime_DateTimeType) < 0)
		return;
	if (PyType_Ready(&PyDateTime_DeltaType) < 0)
		return;
	if (PyType_Ready(&PyDateTime_TimeType) < 0)
		return;
	if (PyType_Ready(&PyDateTime_TZInfoType) < 0)
		return;
	if (PyType_Ready(&PyDateTime_TimeTZType) < 0)
		return;
	if (PyType_Ready(&PyDateTime_DateTimeTZType) < 0)
		return;

	/* Pickling support, via registering functions with copy_reg. */
	{
		PyObject *pickler;
		PyObject *copyreg = PyImport_ImportModule("copy_reg");

		if (copyreg == NULL) return;

		pickler = PyObject_GetAttrString(m, "_date_pickler");
		if (pickler == NULL) return;
		date_unpickler_object = PyObject_GetAttrString(m,
						"_date_unpickler");
		if (date_unpickler_object == NULL) return;
	    	x = PyObject_CallMethod(copyreg, "pickle", "OOO",
	    				&PyDateTime_DateType,
	    				pickler,
		                    	date_unpickler_object);
		if (x == NULL) return;
		Py_DECREF(x);
		Py_DECREF(pickler);

		pickler = PyObject_GetAttrString(m, "_datetime_pickler");
		if (pickler == NULL) return;
		datetime_unpickler_object = PyObject_GetAttrString(m,
						"_datetime_unpickler");
		if (datetime_unpickler_object == NULL) return;
	    	x = PyObject_CallMethod(copyreg, "pickle", "OOO",
	    				&PyDateTime_DateTimeType,
	    				pickler,
		                    	datetime_unpickler_object);
		if (x == NULL) return;
		Py_DECREF(x);
		Py_DECREF(pickler);

		pickler = PyObject_GetAttrString(m, "_time_pickler");
		if (pickler == NULL) return;
		time_unpickler_object = PyObject_GetAttrString(m,
						"_time_unpickler");
		if (time_unpickler_object == NULL) return;
	    	x = PyObject_CallMethod(copyreg, "pickle", "OOO",
	    				&PyDateTime_TimeType,
	    				pickler,
		                	time_unpickler_object);
		if (x == NULL) return;
		Py_DECREF(x);
		Py_DECREF(pickler);

		pickler = PyObject_GetAttrString(m, "_timetz_pickler");
		if (pickler == NULL) return;
		timetz_unpickler_object = PyObject_GetAttrString(m,
						"_timetz_unpickler");
		if (timetz_unpickler_object == NULL) return;
	    	x = PyObject_CallMethod(copyreg, "pickle", "OOO",
	    				&PyDateTime_TimeTZType,
	    				pickler,
		                	timetz_unpickler_object);
		if (x == NULL) return;
		Py_DECREF(x);
		Py_DECREF(pickler);

		pickler = PyObject_GetAttrString(m, "_tzinfo_pickler");
		if (pickler == NULL) return;
		tzinfo_unpickler_object = PyObject_GetAttrString(m,
							"_tzinfo_unpickler");
		if (tzinfo_unpickler_object == NULL) return;
	    	x = PyObject_CallMethod(copyreg, "pickle", "OOO",
	    				&PyDateTime_TZInfoType,
	    				pickler,
		        		tzinfo_unpickler_object);
		if (x== NULL) return;
		Py_DECREF(x);
		Py_DECREF(pickler);

		pickler = PyObject_GetAttrString(m, "_datetimetz_pickler");
		if (pickler == NULL) return;
		datetimetz_unpickler_object = PyObject_GetAttrString(m,
						 "_datetimetz_unpickler");
		if (datetimetz_unpickler_object == NULL) return;
	    	x = PyObject_CallMethod(copyreg, "pickle", "OOO",
	    				&PyDateTime_DateTimeTZType,
	    				pickler,
		                	datetimetz_unpickler_object);
		if (x== NULL) return;
		Py_DECREF(x);
		Py_DECREF(pickler);

		Py_DECREF(copyreg);
	}

	/* timedelta values */
	d = PyDateTime_DeltaType.tp_dict;

	if (PyDict_SetItem(d, safepickle, Py_True) < 0)
		return;

	x = new_delta(0, 0, 1, 0);
	if (x == NULL || PyDict_SetItemString(d, "resolution", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(-MAX_DELTA_DAYS, 0, 0, 0);
	if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(MAX_DELTA_DAYS, 24*3600-1, 1000000-1, 0);
	if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
		return;
	Py_DECREF(x);

	/* date values */
	d = PyDateTime_DateType.tp_dict;

	x = new_date(1, 1, 1);
	if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
		return;
	Py_DECREF(x);

	x = new_date(MAXYEAR, 12, 31);
	if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(1, 0, 0, 0);
	if (x == NULL || PyDict_SetItemString(d, "resolution", x) < 0)
		return;
	Py_DECREF(x);

	/* datetime values */
	d = PyDateTime_DateTimeType.tp_dict;

	x = new_datetime(1, 1, 1, 0, 0, 0, 0);
	if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
		return;
	Py_DECREF(x);

	x = new_datetime(MAXYEAR, 12, 31, 23, 59, 59, 999999);
	if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(0, 0, 1, 0);
	if (x == NULL || PyDict_SetItemString(d, "resolution", x) < 0)
		return;
	Py_DECREF(x);

	/* time values */
	d = PyDateTime_TimeType.tp_dict;

	x = new_time(0, 0, 0, 0);
	if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
		return;
	Py_DECREF(x);

	x = new_time(23, 59, 59, 999999);
	if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(0, 0, 1, 0);
	if (x == NULL || PyDict_SetItemString(d, "resolution", x) < 0)
		return;
	Py_DECREF(x);

	/* timetz values */
	d = PyDateTime_TimeTZType.tp_dict;

	x = new_timetz(0, 0, 0, 0, Py_None);
	if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
		return;
	Py_DECREF(x);

	x = new_timetz(23, 59, 59, 999999, Py_None);
	if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(0, 0, 1, 0);
	if (x == NULL || PyDict_SetItemString(d, "resolution", x) < 0)
		return;
	Py_DECREF(x);

	/* datetimetz values */
	d = PyDateTime_DateTimeTZType.tp_dict;

	x = new_datetimetz(1, 1, 1, 0, 0, 0, 0, Py_None);
	if (x == NULL || PyDict_SetItemString(d, "min", x) < 0)
		return;
	Py_DECREF(x);

	x = new_datetimetz(MAXYEAR, 12, 31, 23, 59, 59, 999999, Py_None);
	if (x == NULL || PyDict_SetItemString(d, "max", x) < 0)
		return;
	Py_DECREF(x);

	x = new_delta(0, 0, 1, 0);
	if (x == NULL || PyDict_SetItemString(d, "resolution", x) < 0)
		return;
	Py_DECREF(x);

	Py_DECREF(safepickle);

	/* module initialization */
	PyModule_AddIntConstant(m, "MINYEAR", MINYEAR);
	PyModule_AddIntConstant(m, "MAXYEAR", MAXYEAR);

	Py_INCREF(&PyDateTime_DateType);
	PyModule_AddObject(m, "date", (PyObject *) &PyDateTime_DateType);

	Py_INCREF(&PyDateTime_DateTimeType);
	PyModule_AddObject(m, "datetime",
			   (PyObject *) &PyDateTime_DateTimeType);

	Py_INCREF(&PyDateTime_DeltaType);
	PyModule_AddObject(m, "timedelta", (PyObject *) &PyDateTime_DeltaType);

	Py_INCREF(&PyDateTime_TimeType);
	PyModule_AddObject(m, "time", (PyObject *) &PyDateTime_TimeType);

	Py_INCREF(&PyDateTime_TZInfoType);
	PyModule_AddObject(m, "tzinfo", (PyObject *) &PyDateTime_TZInfoType);

	Py_INCREF(&PyDateTime_TimeTZType);
	PyModule_AddObject(m, "timetz", (PyObject *) &PyDateTime_TimeTZType);

	Py_INCREF(&PyDateTime_DateTimeTZType);
	PyModule_AddObject(m, "datetimetz",
			   (PyObject *)&PyDateTime_DateTimeTZType);

	/* A 4-year cycle has an extra leap day over what we'd get from
	 * pasting together 4 single years.
	 */
	assert(DI4Y == 4 * 365 + 1);
	assert(DI4Y == days_before_year(4+1));

	/* Similarly, a 400-year cycle has an extra leap day over what we'd
	 * get from pasting together 4 100-year cycles.
	 */
	assert(DI400Y == 4 * DI100Y + 1);
	assert(DI400Y == days_before_year(400+1));

	/* OTOH, a 100-year cycle has one fewer leap day than we'd get from
	 * pasting together 25 4-year cycles.
	 */
	assert(DI100Y == 25 * DI4Y - 1);
	assert(DI100Y == days_before_year(100+1));

	us_per_us = PyInt_FromLong(1);
	us_per_ms = PyInt_FromLong(1000);
	us_per_second = PyInt_FromLong(1000000);
	us_per_minute = PyInt_FromLong(60000000);
	seconds_per_day = PyInt_FromLong(24 * 3600);
	if (us_per_us == NULL || us_per_ms == NULL || us_per_second == NULL ||
	    us_per_minute == NULL || seconds_per_day == NULL)
		return;

	/* The rest are too big for 32-bit ints, but even
	 * us_per_week fits in 40 bits, so doubles should be exact.
	 */
	us_per_hour = PyLong_FromDouble(3600000000.0);
	us_per_day = PyLong_FromDouble(86400000000.0);
	us_per_week = PyLong_FromDouble(604800000000.0);
	if (us_per_hour == NULL || us_per_day == NULL || us_per_week == NULL)
		return;
}