On 2022-04-14, MRAB <pyt...@mrabarnett.plus.com> wrote: > On 2022-04-14 16:22, Jon Ribbens via Python-list wrote: >> On 2022-04-14, Paul Bryan <pbr...@anode.ca> wrote: >>> I think because minutes and hours can easily be composed by multiplying >>> seconds. days is separate because you cannot compose days from seconds; >>> leap seconds are applied to days at various times, due to >>> irregularities in the Earth's rotation. >> >> That's an argument that timedelta should *not* have a 'days' attribute, >> because a day is not a fixed number of seconds long (to know how long >> a day is, you have to know which day you're talking about, and where). >> It's an undocumented feature of timedelta that by 'day' it means '86400 >> seconds'. > > When you're working only with dates, timedelta not having a 'days' > attribute would be annoying, especially when you consider that a day is > usually 24 hours, but sometimes 23 or 25 hours (DST).
The second half of your sentence is the argument as to why the first half of your sentence is wrong. The difference between noon on the 26th March 2022 in London and noon on the 27th March 2022 is "1 day" from one point of view but is not "1 day" according to timedelta. -- https://mail.python.org/mailman/listinfo/python-list
