Here's a proposed patch to try to address the problem with Moroccan DST. I've pushed this to the unofficial github version of the tz database. === * africa (Morocco): Use GNU Emacs 24.3 to estimate Ramadan-based DST transition dates for 2013-2038. Heads-up by Erik Homoet in <http://mm.icann.org/pipermail/tz/2013-February/018680.html>. --- africa | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 54 insertions(+), 1 deletion(-) diff --git a/africa b/africa index f378cc4..5f4f8eb 100644 --- a/africa +++ b/africa @@ -846,6 +846,41 @@ Zone Indian/Mayotte 3:00:56 - LMT 1911 Jul # Mamoutzou # 3:00 am Friday, July 20, 2012 and will again be advanced by 60 minutes # August 20, 2012 from 2:00 am. +# From Paul Eggert (2013-03-06): +# Morocco's daylight-saving transitions due to Ramadan seem to be +# announced a bit in advance. On 2012-07-11 the Moroccan government +# announced that year's Ramadan daylight-saving transitions would be +# 2012-07-20 and 2012-08-20; see +# <http://www.mmsp.gov.ma/fr/actualites.aspx?id=288>. +# +# To estimate what the Moroccan government will do in future years, +# transition dates for 2013 through 2021 were determined by running +# the following program under GNU Emacs 24.3: +# +# (let ((islamic-year 1434)) +# (while (< islamic-year 1444) +# (let ((a +# (calendar-gregorian-from-absolute +# (calendar-islamic-to-absolute (list 9 1 islamic-year)))) +# (b +# (calendar-gregorian-from-absolute +# (calendar-islamic-to-absolute (list 10 1 islamic-year))))) +# (insert +# (format +# (concat "Rule\tMorocco\t%d\tonly\t-\t%s\t %2d\t 3:00\t0\t-\n" +# "Rule\tMorocco\t%d\tonly\t-\t%s\t %2d\t 2:00\t1:00\tS\n") +# (car (cdr (cdr a))) (calendar-month-name (car a) t) (car (cdr a)) +# (car (cdr (cdr b))) (calendar-month-name (car b) t) (car (cdr b))))) +# (setq islamic-year (+ 1 islamic-year)))) +# +# with the results hand-edited for 2020-2022, when the normal spring-forward +# date falls during the estimated Ramadan. +# +# From 2023 through 2038 Ramadan is not predicted to overlap with +# daylight saving time. Starting in 2039 there will be overlap again, +# but 32-bit time_t values roll around in 2038 so for now do not worry +# about dates after 2038. + # RULE NAME FROM TO TYPE IN ON AT SAVE LETTER/S Rule Morocco 1939 only - Sep 12 0:00 1:00 S @@ -871,10 +906,28 @@ Rule Morocco 2010 only - May 2 0:00 1:00 S Rule Morocco 2010 only - Aug 8 0:00 0 - Rule Morocco 2011 only - Apr 3 0:00 1:00 S Rule Morocco 2011 only - Jul 31 0 0 - -Rule Morocco 2012 max - Apr lastSun 2:00 1:00 S +Rule Morocco 2012 2019 - Apr lastSun 2:00 1:00 S Rule Morocco 2012 max - Sep lastSun 3:00 0 - Rule Morocco 2012 only - Jul 20 3:00 0 - Rule Morocco 2012 only - Aug 20 2:00 1:00 S +Rule Morocco 2013 only - Jul 9 3:00 0 - +Rule Morocco 2013 only - Aug 8 2:00 1:00 S +Rule Morocco 2014 only - Jun 29 3:00 0 - +Rule Morocco 2014 only - Jul 29 2:00 1:00 S +Rule Morocco 2015 only - Jun 18 3:00 0 - +Rule Morocco 2015 only - Jul 18 2:00 1:00 S +Rule Morocco 2016 only - Jun 7 3:00 0 - +Rule Morocco 2016 only - Jul 7 2:00 1:00 S +Rule Morocco 2017 only - May 27 3:00 0 - +Rule Morocco 2017 only - Jun 26 2:00 1:00 S +Rule Morocco 2018 only - May 16 3:00 0 - +Rule Morocco 2018 only - Jun 15 2:00 1:00 S +Rule Morocco 2019 only - May 6 3:00 0 - +Rule Morocco 2019 only - Jun 5 2:00 1:00 S +Rule Morocco 2020 only - May 24 2:00 1:00 S +Rule Morocco 2021 only - May 13 2:00 1:00 S +Rule Morocco 2022 only - May 3 2:00 1:00 S +Rule Morocco 2023 max - Apr lastSun 2:00 1:00 S # Zone NAME GMTOFF RULES FORMAT [UNTIL] Zone Africa/Casablanca -0:30:20 - LMT 1913 Oct 26 -- 1.7.11.7