On Mon, Jul 27, 2015 at 12:30 PM, Lennart Regebro <regebro@gmail.com> wrote:
On Mon, Jul 27, 2015 at 6:15 PM, Nikolaus Rath <Nikolaus@rath.org> wrote:
> On Jul 27 2015, Lennart Regebro <regebro@gmail.com> wrote:
(The *first* option) 
>> That you add one hour to it, and the datetime moves forward one hour
>> in actual time? That's doable, but during certain circumstance this
>> may mean that you go from 1AM to 1AM, or from 1AM to 3AM.
>>
(The *second* option) 
>> Or do you expect that adding one hour will increase the hour count
>> with one, ie that the "wall time" increases with one hour? ...
> Can you tell us which of the two operations datetime currently
> implements?

It's intended that the first one is implemented, meaning that
datetime.now() + timedelta(hours=24) can result in a datetime
somewhere between 23 and 25 hours into the future.

I think this describes what was originally your *second*, not *first* option. It
will also help if you focus on one use case at a time.  Your original example
dealt with adding 1 hour, but now you switch to adding 24.

In my previous email, I explained what is currently doable using the datetime
module:

>>> t = datetime(2014,11,2,5,tzinfo=timezone.utc).astimezone()
>>> t.strftime("%D %T%z %Z")
'11/02/14 01:00:00-0400 EDT'
>>> (t+timedelta(hours=1)).astimezone().strftime("%D %T%z %Z")
'11/02/14 01:00:00-0500 EST'

Is this your *first* or your *second* option?  Note that this is not what
is "intended".  This is an actual Python 3.4.3 session.