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-rw-r--r--Build/source/libs/icu/icu-src/source/tools/tzcode/icuzones49
1 files changed, 49 insertions, 0 deletions
diff --git a/Build/source/libs/icu/icu-src/source/tools/tzcode/icuzones b/Build/source/libs/icu/icu-src/source/tools/tzcode/icuzones
index 9e3c7c9c725..168a86f9181 100644
--- a/Build/source/libs/icu/icu-src/source/tools/tzcode/icuzones
+++ b/Build/source/libs/icu/icu-src/source/tools/tzcode/icuzones
@@ -78,3 +78,52 @@ Link Asia/Ho_Chi_Minh VST
#
Link America/Regina Canada/East-Saskatchewan # removed from backward in 2017c
+
+# Note:
+# Following section was added for tz database 2018a and 2018b.
+# ICU has a bug handling negative DST, and we also don't want to
+# flip sumer time name and winter time name for Dublin at least for
+# now. Because the change had major impacts to tz database external
+# consumers, the tz database maintainer once reverted the Europe/Dublin
+# rules (same as 2017c or older) in 2018c. The tz database maintainer
+# thinks the changes in 2018a should be brought back when external
+# tz database consumers are ready to adopt the change. We don't know
+# what CLDR TC want to do with this for now. But if tz database brings
+# back the change, and CLDR TC (and ICU TC) want to keep the display name
+# unchanged, then we can uncomment the block below to restore ICU
+# custom override. (Yoshito 2018-01-23)
+
+#
+# tzdata2018a changed Europe/Dublin to use IST (UTC+1) as the standard time
+# of the region, and GMT (UTC) as the daylight saving time with negative
+# offset (-1 hour) in winter. ICU SimpleTimeZone rejects a zone with negative
+# daylight saving time offset. We could remove the restriction in newer version
+# of ICU, but such data does not work well with older ICU runtime without
+# fixing the issue. For now, we define our own Europe/Dubin in ICU, replacing
+# Europe/Dublin data from the tz database.
+#
+
+# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
+# Rule Eire--ICU 1971 only - Oct 31 2:00u 0 GMT
+# Rule Eire--ICU 1972 1980 - Mar Sun>=16 2:00u 1:00 IST
+# Rule Eire--ICU 1972 1980 - Oct Sun>=23 2:00u 0 GMT
+# Rule Eire--ICU 1981 max - Mar lastSun 1:00u 1:00 IST
+# Rule Eire--ICU 1981 1989 - Oct Sun>=23 1:00u 0 GMT
+# Rule Eire--ICU 1990 1995 - Oct Sun>=22 1:00u 0 GMT
+# Rule Eire--ICU 1996 max - Oct lastSun 1:00u 0 GMT
+
+# Zone NAME GMTOFF RULES FORMAT [UNTIL]
+# Zone Europe/Dublin--ICU -0:25:00 - LMT 1880 Aug 2
+# -0:25:21 - DMT 1916 May 21 2:00s
+# -0:25:21 1:00 IST 1916 Oct 1 2:00s
+# 0:00 GB-Eire %s 1921 Dec 6 # independence
+# 0:00 GB-Eire GMT/IST 1940 Feb 25 2:00s
+# 0:00 1:00 IST 1946 Oct 6 2:00s
+# 0:00 - GMT 1947 Mar 16 2:00s
+# 0:00 1:00 IST 1947 Nov 2 2:00s
+# 0:00 - GMT 1948 Apr 18 2:00s
+# 0:00 GB-Eire GMT/IST 1968 Oct 27
+# 0:00 Eire--ICU GMT/IST
+
+# Link Europe/Dublin--ICU Eire--ICU
+