datetime.timedelta is now subclassable in Python. The new test shows
one good use: a subclass adding a method to express the duration as
a number of hours (or minutes, or whatever else you want to add). The
native breakdown into days+seconds+us is often clumsy. Incidentally
moved a large chunk of object-initialization code closer to the top of
the file, to avoid worse forward-reference trickery.
diff --git a/Misc/NEWS b/Misc/NEWS
index e182845..02f845d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -26,8 +26,8 @@
Extension modules
-----------------
-- The datetime.datetime and datetime.time classes are now properly
- subclassable.
+- The datetime module classes datetime, time, and timedelta are now
+ properly subclassable.
- _tkinter.{get|set}busywaitinterval was added.