On Mon, Feb 26, 2018 at 8:55 PM, Ian Kelly <ian.g.ke...@gmail.com> wrote: > On Mon, Feb 26, 2018 at 8:09 PM, Steven D'Aprano > <steve+comp.lang.pyt...@pearwood.info> wrote: >> Yes you did: "the last second of every year" is always 23:59:59 of 31st >> December, and it is always the same time and date "every year". > > Except when it's 23:59:60 or 23:59:61 (which hasn't yet happened but could).
Actually, after doing some reading on the subject just now, I learned that double leap seconds don't actually exist! They were accidentally invented by the drafters of the ANSI C standard and later propagated to the POSIX standard and the ANSI SQL standard. https://www.ucolick.org/~sla/leapsecs/timescales.html#UTC So the actual last second of the year must always be one of 23:59:58, 23:59:59 or 23:59:60. (Hint: although we've never had a negative leap second to date, don't schedule your database update for 23:59:59 if you want to ensure that it actually happens.) -- https://mail.python.org/mailman/listinfo/python-list
