How to add delta to python datetime.time?

Question

From:

http://docs.python.org/py3k/library/datetime.html#timedelta-objects

A timedelta object represents a duration, the difference between two dates or times.

So why i get error with this:

>>> from datetime import datetime, timedelta, time >>> datetime.now() + timedelta(hours=12) datetime.datetime(2012, 9, 17, 6, 24, 9, 635862) >>> datetime.now().date() + timedelta(hours=12) datetime.date(2012, 9, 16)  >>> datetime.now().time() + timedelta(hours=12) Traceback (most recent call last):   File "<stdin>", line 1, in <module> TypeError: unsupported operand type(s) for +: 'datetime.time' and 'datetime.timedelta' 

Answer 1

datetime.time objects do not support addition with datetime.timedeltas.

There is one natural definition though, clock arithmetic. You could compute it like this:

import datetime as dt now = dt.datetime.now() delta = dt.timedelta(hours = 12) t = now.time() print(t) # 12:39:11.039864  print((dt.datetime.combine(dt.date(1,1,1),t) + delta).time()) # 00:39:11.039864 

dt.datetime.combine(...) lifts the datetime.time t to a datetime.datetime object, the delta is then added, and the result is dropped back down to a datetime.time object.

Answer 2

All the solutions above are too complicated, OP had already shown that we can do calculation between datetime.datetime and datetime.timedelta, so why not just do:

(datetime.now() + timedelta(hours=12)).time()