[tz] Egypt to change back to Daylight system!

[Paul Eggert]

Thanks for the citation.  I pushed the attached patch to the 
experimental tz release on github.  There's a lot of guesswork in this 
one, and comments are welcome.  It looks like we'll need a new official 
release soon.
-------------- next part --------------
From c9ebcee69b5f692cefc006ba738af70aa9970c80 Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert at cs.ucla.edu>
Date: Wed, 7 May 2014 18:09:14 -0700
Subject: [PATCH] africa: Egypt resumes DST on May 15

(Thanks to Ahmad El-Dardiry.)
* NEWS: Document this.
* africa (Egypt): Add rules for 2014 through 2038.  They all
involve some guesswork, unfortunately.
---
 NEWS   | 10 ++++++++++
 africa | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/NEWS b/NEWS
index 2c289f5..3fdf592 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,16 @@ News for the tz database
 
 Unreleased, experimental changes
 
+  Changes affecting near-future time stamps
+
+    Egypt observes DST starting May 15.  (Thanks to Ahmad El-Dardiry.)
+    Details have not been announced, except that DST will not be observed
+    during Ramadan.  Guess that DST will stop during the same Ramadan dates as
+    Morocco, and that Egypt's future spring and fall transitions will be the
+    same as 2010 when it last observed DST, namely April's last Friday at
+    00:00 to September's last Thursday at 23:00 standard time.  Also, guess
+    that Ramadan transitions will be at 00:00 standard time.
+
   Changes affecting code
 
     zic now generates transitions for minimum time values, eliminating guesswork
diff --git a/africa b/africa
index fbf0b65..eefaf0d 100644
--- a/africa
+++ b/africa
@@ -335,11 +335,52 @@ Rule	Egypt	2007	only	-	Sep	Thu>=1	23:00s	0	-
 # http://www.worldtimezone.com/dst_news/dst_news_egypt02.html
 # </a>
 
+# From Ahmad El-Dardiry (2014-05-07):
+# Egypt is to change back to Daylight system on May 15
+# http://english.ahram.org.eg/NewsContent/1/64/100735/Egypt/Politics-/Egypts-government-to-reapply-daylight-saving-time-.aspx
+
+# From Paul Eggert (2014-05-07):
+# Sarah El Deeb and Lee Keath of AP report that the Egyptian government says
+# the change is because of blackouts in Cairo, even though Ahram Online (cited
+# above) says DST had no affect on electricity consumption.  The AP story says
+# DST will not be observed during Ramadan.  There is no information about when
+# DST will end.  See:
+# http://abcnews.go.com/International/wireStory/el-sissi-pushes-egyptians-line-23614833
+#
+# For now, assume DST will start at 00:00 on May 15, and guess that in future
+# years DST will start and end using the same rules as 2010, and guess that
+# Egypt will agree with Morocco (see below) about the date Ramadan starts and
+# ends, though (unlike Morocco) it will switch at 00:00 standard time.  In
+# Egypt the spring-forward transitions are removed for 2020-2022, when the
+# guessed spring-forward date falls during the estimated Ramadan, and all
+# transitions removed for 2023-2038, where the estimated Ramadan falls entirely
+# outside the guessed daylight-saving time.  Ramadan intrudes on the guessed
+# DST starting in 2039, but that's beyond our somewhat-arbitrary cutoff.
+
 Rule	Egypt	2008	only	-	Aug	lastThu	23:00s	0	-
 Rule	Egypt	2009	only	-	Aug	20	23:00s	0	-
 Rule	Egypt	2010	only	-	Aug	11	0:00	0	-
 Rule	Egypt	2010	only	-	Sep	10	0:00	1:00	S
 Rule	Egypt	2010	only	-	Sep	lastThu	23:00s	0	-
+Rule	Egypt	2014	only	-	May	15	 0:00s	1:00	S
+Rule	Egypt	2014	only	-	Jun	29	 0:00s	0	-
+Rule	Egypt	2014	only	-	Jul	29	 0:00s	1:00	S
+Rule	Egypt	2014	max	-	Sep	lastThu	23:00s	0	-
+Rule	Egypt	2015	2019	-	Apr	lastFri	 0:00s	1:00	S
+Rule	Egypt	2015	only	-	Jun	18	 0:00s	0	-
+Rule	Egypt	2015	only	-	Jul	18	 0:00s	1:00	S
+Rule	Egypt	2016	only	-	Jun	 7	 0:00s	0	-
+Rule	Egypt	2016	only	-	Jul	 7	 0:00s	1:00	S
+Rule	Egypt	2017	only	-	May	27	 0:00s	0	-
+Rule	Egypt	2017	only	-	Jun	26	 0:00s	1:00	S
+Rule	Egypt	2018	only	-	May	16	 0:00s	0	-
+Rule	Egypt	2018	only	-	Jun	15	 0:00s	1:00	S
+Rule	Egypt	2019	only	-	May	 6	 0:00s	0	-
+Rule	Egypt	2019	only	-	Jun	 5	 0:00s	1:00	S
+Rule	Egypt	2020	only	-	May	24	 0:00s	1:00	S
+Rule	Egypt	2021	only	-	May	13	 0:00s	1:00	S
+Rule	Egypt	2022	only	-	May	 3	 0:00s	1:00	S
+Rule	Egypt	2023	max	-	Apr	lastFri	 0:00s	1:00	S
 
 # Zone	NAME		GMTOFF	RULES	FORMAT	[UNTIL]
 Zone	Africa/Cairo	2:05:09 -	LMT	1900 Oct
-- 
1.9.1