Fix: #1836: Off-by-one bug in TimedRotatingFileHandler rollover calculation. Patch thanks to Kathryn M. Kowalski.
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index fa203cf..93fcd83 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -228,13 +228,16 @@
# Days to rollover is 6 - 5 + 3, or 4. In this case, it's the
# number of days left in the current week (1) plus the number
# of days in the next week until the rollover day (3).
+ # The calculations described in 2) and 3) above need to have a day added.
+ # This is because the above time calculation takes us to midnight on this
+ # day, i.e. the start of the next day.
if when.startswith('W'):
day = t[6] # 0 is Monday
if day != self.dayOfWeek:
if day < self.dayOfWeek:
- daysToWait = self.dayOfWeek - day - 1
+ daysToWait = self.dayOfWeek - day
else:
- daysToWait = 6 - day + self.dayOfWeek
+ daysToWait = 6 - day + self.dayOfWeek + 1
self.rolloverAt = self.rolloverAt + (daysToWait * (60 * 60 * 24))
#print "Will rollover at %d, %d seconds from now" % (self.rolloverAt, self.rolloverAt - currentTime)