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.