[tz] Egypt transitions around Ramadan don't match timeanddate.com

Paul Eggert eggert at cs.ucla.edu
Thu Apr 2 05:10:13 UTC 2015

On 04/01/2015 11:26 AM, Matt Johnson wrote:
> The Egyptian government may use the Ramadan dates to decide when DST will 
> change, but my guess is that DST will end *before* Ramadan, and resume *after*.

Yes, that's the basis for the guess in the tz database; since Ramadan probably 
starts June 18, a clock transition at 24:00 on June 18 would mean the first day 
of Ramadan wouldn't be covered, so we guess that the clock transition will 
happen at 24:00 the previous Thursday (June 11).  Admittedly the start of 
Ramadan observance is more complicated than this brief summary implies; still, 
this is the approximation that the tz database is currently documented to be 
using (for more info please see the GNU Emacs Lisp source code in the comments).

We won't know if this guess is correct until the Egyptian authorities announce 
their plan.  For lack of better info it's probably better to leave the tz 
database alone for now.

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