[tz] Timezones Morocco 2013 incorrect
Patrice Scattolin
patrice.scattolin at oracle.com
Thu Mar 7 18:30:10 UTC 2013
On 07/03/2013 1:33 AM, Paul Eggert wrote:
> On 03/06/2013 09:13 AM, Patrice Scattolin wrote:
>
>> Since we have no idea of emacs' algorithm
> We have the source code, so we can get an idea.
> The code can be found here:
>
> http://bzr.savannah.gnu.org/lh/emacs/trunk/annotate/head:/lisp/calendar/cal-islam.el
Ah yes, lisp! http://xkcd.com/297/
> Dershowitz and Reingold mention that there are other arithmetical
> approximations. In particular, some Microsoft products
> use a variant approximation. So it appears that no matter which
> approximation we'll use, we're bound to disagree with somebody's
> else's prediction.
The age and position of the moon are accurate enough (even with Meeus
who is accurate enough for amateur planetarium software but notably not
enough for more exacting tasks). It's the criteria upon when the moon
crescent is actually observable that is up for debate. Since this relies
most on the observer's skills, no matter who's approximation we rely
upon we can certainly get it wrong by a day on some occasions.
Apparently beginning of the Ramadan is a waiting game anyways
http://insidethemiddleeast.blogs.cnn.com/2012/07/19/muslims-prepare-to-observe-ramadan-whenever-it-starts/
so I doubt we can actually do better no matter algorithm.
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