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:
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.
Or do you expect that adding one hour will increase the hour count with one, ie that the "wall time" increases with one hour? This may actually leave you with a datetime that does not exist, so that is not something you can consistently do.
Apologies for asking yet another dumb question about this, but I have the impression that a lot of other people are struggling with the basics here too.
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. Or well, any amount, in theory, I guess some changes are more than an hour, but that's very unusual.
And when people talk about explicitly converting to UTC and back, does that mean that if you're (again, with the current implementation) converting to UTC, *then* add the one hour, and then convert back, you get the other operation (that you don't get when you directly add 1 day)?
Yes, exactly. //Lennart