remove minutes and seconds from datetime python

old_date = datetime.datetime(2011, 3, 23, 16, 45)
new_date = old_date.replace(minute=0, second=0) + datetime.timedelta(hours=1)

Here is what the above code is Doing:
1. We create a datetime object for the old date.
2. We create a new datetime object for the new date by replacing the minute and second values with 0 and adding 1 hour to the old date.