[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#16663: emacs/calc/date
From: |
Jay Belanger |
Subject: |
bug#16663: emacs/calc/date |
Date: |
Wed, 05 Feb 2014 22:03:33 -0600 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux) |
> (What I think I'm doing is creating a vector with 10 year increments,
> in
> seconds, and wanted to know if you honored, or don't honor, leap
> seconds.
It doesn't honor leap seconds. The manual points out:
Today's timekeepers introduce an occasional “leap second” as well,
but Calc does not take these minor effects into account. (If it did,
it would have to report a non-integer number of days between, say,
‘<12:00am Mon Jan 1, 1900>’ and ‘<12:00am Sat Jan 1, 2000>’.)
Maybe more importantly, leap seconds are unpredictable.
> It appears to me that the answer is no. I'm just surprised to
> see the additional shift of an hour shift at 1630 - 1640 and
> 2199-2209.
>
> why?)
>
> ...
These are during daylight savings time:
> <8:00pm Sun Mar 18, 1610>,
> <8:00pm Wed Mar 15, 1620>,
> <8:00pm Sat Mar 13, 1630>,
These are not during daylight savings time:
> <7:00pm Tue Mar 10, 1640>,
> <7:00pm Fri Mar 8, 1650>,
> <7:00pm Mon Mar 5, 1660>,
> ...
> <7:00pm Wed Nov 10, 2179>,
> <7:00pm Sat Nov 7, 2189>,
> <7:00pm Tue Nov 5, 2199>,
These are during daylight savings time:
> <8:00pm Fri Nov 3, 2209>,
> <8:00pm Mon Nov 1, 2219>,
> <8:00pm Thu Oct 29, 2229>,
> ...
>
> My question was 'and does the conversion include leap seconds'. The
> answer appears to be 'no', but the 7pm/8pm conversions seem odd.
The hour differences are because of daylight savings time.
Jay
bug#16663: emacs/calc/date, Jay Belanger, 2014/02/07