How to use Python to calculate time

Question

I want to write python script that acts as a time calculator.

For example:

Suppose the time is now 13:05:00

I want to add 1 hour, 23 minutes, and 10 seco

Answer 1

datetime.timedelta is designed for fixed time differences (e.g. 1 day is fixed, 1 month is not).

>>> import datetime
>>> t = datetime.time(13, 5)
>>> print t
13:05:00
>>> now = datetime.datetime.now()
>>> print now
2009-11-17 13:03:02.227375
>>> print now + datetime.timedelta(hours=1, minutes=23, seconds=10)
2009-11-17 14:26:12.227375

Note that it doesn't make sense to do addition on just a time (but you can combine a date and a time into a datetime object, use that, and then get the time). DST is the major culprit. For example, 12:01am + 5 hours could be 4:01am, 5:01am, or 6:01am on different days.