Re: date %d day question

[Tapani Tarvainen]

On Tue, Oct 29, 2024 at 08:43:37PM -0400, Greg Wooledge (greg@wooledge.org) 
wrote:

> February has 28 days, except in "leap years", where it has 29 days.

> The estimate of "every 4th year" was used before the Gregorian calendar,
> and it turned out to be noticeably wrong.  The adjustment to remove 3
> leap years every 400 years is what differentiates the Gregorian calendar
> from the Julian calendar that was used previously.

Yes. An amusing anecdote: Sweden decided to switch to the Gregorian
calendar in 1700, but to minimize confusion, they decided to move
adjust the calendar gradually, one day at a time every four years, and
started by skipping February 29 on 1700. They failed to follow up in
the following years however, and by 1711 they realized it was not a
good idea to begin with, as their calendar was out of sync with
everybody.

Then instead of jumping ahead they decided to go back to the Julian
calendar, and they did so by having an extra leap day on 1712, making
it a 367-day year with February 30.

As far as I know it's the only occurrence of February 30 anywhere.

-- 
Tapani Tarvainen