proposed tz changes for Israel, Mexico, Simferopol, etc.
Paul Eggert
eggert at twinsun.com
Thu Jul 27 17:19:54 UTC 2000
The Israeli daylight-saving changes prompted me to collect all the
proposed changes that have been accumulating to the tz data. Here
they are:
* New daylight saving rules for Israel starting this fall.
(Thanks to Ephraim Silverberg for this info.)
* New zones America/Merida and America/Monterrey, to account for 1980s
Mexican daylight saving time experiments that we previosly didn't
know about. Also, add 23 days to the date of the April 1942
transition in Mexico. (Thanks to Gwillim Law for this info.)
* Fix a glitch in the March 1997 transition for Europe/Simferopol,
which incorrectly changed the clocks twice. (Thanks to Gwillim Law
for catching this bug.)
The following changes affect commentary only:
* Refer to ZoneInfo, a new Java-based tz file reader.
* Refer to the new computer version of Shanks's excellent time zone data.
* Refer to the new Leap Second Discussion mailing list.
* Report the Economist's incorrect story about DST in Iraqi Kurdistan,
and report Rives McDow's refutation.
* Report a legal citation for the 2000/2001 Tasmanian rules
(thanks to Sim Alam for this info).
* Fix typos in commentary about Iran, and update URL.
===================================================================
RCS file: RCS/zone.tab,v
retrieving revision 2000.1
retrieving revision 2000.1.0.1
diff -pu -r2000.1 -r2000.1.0.1
--- zone.tab 2000/01/18 14:21:22 2000.1
+++ zone.tab 2000/07/27 17:08:27 2000.1.0.1
@@ -247,6 +247,8 @@ MV +0410+07330 Indian/Maldives
MW -1547+03500 Africa/Blantyre
MX +1924-09909 America/Mexico_City Central Time - most locations
MX +2105-08646 America/Cancun Central Time - Quintana Roo
+MX +2058-08937 America/Merida Central Time - Campeche, Yucatan
+MX +2540-10019 America/Monterrey Central Time - Coahuila, Durango, Nuevo Leon, Tamaulipas
MX +2313-10625 America/Mazatlan Mountain Time - S Baja, Nayarit, Sinaloa
MX +2838-10605 America/Chihuahua Mountain Time - Chihuahua
MX +2904-11058 America/Hermosillo Mountain Standard Time - Sonora
===================================================================
RCS file: RCS/northamerica,v
retrieving revision 2000.3
retrieving revision 2000.3.0.1
diff -pu -r2000.3 -r2000.3.0.1
--- northamerica 2000/03/04 15:31:08 2000.3
+++ northamerica 2000/07/27 17:08:27 2000.3.0.1
@@ -1002,52 +1002,35 @@ Zone America/Dawson -9:17:40 - LMT 1900
# Mexico
-# From Guy Harris:
-# Rules are from the Official Airline Guide, Worldwide Edition, for 1987.
-# Rules [before] 1987 are unknown.
-# The comments in the OAG say "Only Ensenada, Mexicale, San Felipe and Tijuana
-# observe DST." This is presumably Baja California Norte, above 28th parallel,
-# as listed there; [there is also] "Baja California Sur and N. Pacific
-# Coast (States of Sinaloa and Sonora)."
-
-# From Bob Devine (1988-01-28):
-# The Federal District (where Mexico City is) has observed [DST] several
-# times but not recently.
-#
-# I don't where to draw the line in the North Baja area. 28th latitude
-# sounds good -- but it may be higher (how far [d]o radio stations from
-# San Diego affect culture?).
-#
-# The dates of DST probably go back to 1981. The rules are the same as
-# US's. This is going to be a headache for US presidential electi[o]n years!
-
-# From Arthur David Olson (1988-02-13)
-# Since the 1981 starting date is only "probable," we'll keep the 1987
-# starting date below.
-
-# From U. S. Naval Observatory (1989-01-19):
-# MEXICO BAJA CAL N 7 H BEHIND UTC BAJA CALIFORNIA SUR AND
-# MEXICO BAJA CAL N N. PACIFIC COAST (STATES
-# MEXICO BAJA CAL N OF SINALOA AND SONORA)
-# MEXICO BAJA CAL N 8 H BEHIND UTC ABOVE 28TH PARALLEL APR 3
-# MEXICO BAJA CAL N - OCT 29
-# MEXICO BAJA CAL N 7 H BEHIND UTC ABOVE 28TH PARALLEL APR 3
-# MEXICO BAJA CAL N - 0CT 29
-# MEXICO 6 H BEHIND UTC STATES OF DURANGO,
-# MEXICO COAHUILA, NUEVO LEON,
-# MEXICO TAMAULIPAS
-# MEXICO 5 H BEHIND UTC STATES OF DURANGO,
-# MEXICO COAHUILA, NUEVO LEON,
-# MEXICO TAMAULIPAS APR 3 - OCT 29
-# MEXICO 6 H BEHIND UTC GENERAL MEXICO, STATES OF
-# MEXICO CAMPECHE, QUINTANA ROO AND
-# MEXICO YUCATAN
-
-# From Arthur David Olson (1989-01-21):
-# April 3 fell on a Sunday in 1988; October 29 fell on a Sunday in 1989. Ahem.
-# USNO claims there should be four Mexican zones rather than three:
-# a zone that's GMT-8 with DST; a zone that's always GMT-7;
-# a zone that's GMT-6 with DST; and a zone that's always GMT-6.
+# Gwillim Law reports this source for daylight saving time in Mexico:
+# <a href="http://www.spin.com.mx/verano/">
+# Daylight saving time * SPIN-Internet (in Spanish)
+# </a>
+# Law (2000-03-09) translates it as follows:
+#
+# Standard time effective in Mexico takes its origin in the
+# presidential decree of April 24, 1942. The time of the 120th
+# meridian applies to the state of Baja California; of the 105th
+# meridian to the states of Baja California Sur, Sonora, Sinaloa, and
+# Nayarit; and the time of the 90th meridian to the rest of the
+# country.
+#
+# In the country, there have been several attempts made to adapt
+# standard time with the object of arriving at a better use of
+# daylight for social and economic activities. In December, 1981 a
+# permanent time zone was decreed for the states of Campeche, Yucatan,
+# and Quintana Roo, displacing them from the 90th to the 75th
+# meridian. This disposition was annulled on December 2, 1982.
+#
+# In 1988 a Summer Time was established for the states of Tamaulipas,
+# Nuevo Leon, Coahuila, and Durango, which meant that from the first
+# Sunday in April to the last [Sunday] of October those states
+# displaced their time from the 90th to the 75th meridian. That
+# disposition lasted for one year.
+
+# From Paul Eggert (2000-07-26):
+# Shanks gives 1942-04-01 instead of 1942-04-24, and omits the 1981
+# and 1988 DST experiments. Go with spin.com.mx.
# From Alan Perry <alan.perry at eng.sun.com> (1996-02-15):
# A guy from our Mexico subsidiary finally found the Presidential Decree
@@ -1093,7 +1076,6 @@ Zone America/Dawson -9:17:40 - LMT 1900
# savings time so as to stay on the same time zone as the southern part of
# Arizona year round.
-# From Shanks:
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Mexico 1939 only - Feb 5 0:00 1:00 D
Rule Mexico 1939 only - Jun 25 0:00 0 S
@@ -1111,10 +1093,22 @@ Rule BajaN 1954 1961 - Sep lastSun 2:00
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
# Quintana Roo
Zone America/Cancun -5:47:04 - LMT 1922 Jan 1 0:12:56
+ -6:00 - CST 1981 Dec
+ -5:00 - EST 1982 Dec 2
-6:00 - CST 1996
-6:00 Mexico C%sT 1997 Oct lastSun 2:00
-5:00 Mexico E%sT 1998 Aug 2 2:00
-6:00 Mexico C%sT
+# Campeche, Yucatan
+Zone America/Merida -5:58:28 - LMT 1922 Jan 1 0:01:32
+ -6:00 - CST 1981 Dec
+ -5:00 - EST 1982 Dec 2
+ -6:00 Mexico C%sT
+# Coahuila, Durango, Nuevo Leon, Tamaulipas
+Zone America/Monterrey -6:41:16 - LMT 1922 Jan 1 0:01:32
+ -6:00 - CST 1988
+ -6:00 US C%sT 1989
+ -6:00 Mexico C%sT
# Central Mexico
Zone America/Mexico_City -6:36:36 - LMT 1922 Jan 1 0:23:24
-7:00 - MST 1927 Jun 10 23:00
@@ -1141,19 +1135,19 @@ Zone America/Hermosillo -7:23:52 - LMT 1
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Mar 30 23:00
- -6:00 - CST 1942 Apr
+ -6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT 1999
-7:00 - MST
-# S Baja California, Nayarit, Sinaloa
+# Baja California Sur, Nayarit, Sinaloa
Zone America/Mazatlan -7:05:40 - LMT 1921 Dec 31 23:54:20
-7:00 - MST 1927 Jun 10 23:00
-6:00 - CST 1930 Nov 15
-7:00 - MST 1931 May 1 23:00
-6:00 - CST 1931 Oct
-7:00 - MST 1932 Mar 30 23:00
- -6:00 - CST 1942 Apr
+ -6:00 - CST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 - PST 1970
-7:00 Mexico M%sT
@@ -1161,7 +1155,7 @@ Zone America/Mazatlan -7:05:40 - LMT 192
Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 0:11:56
-8:00 - PST 1927 Jun 10 23:00
-7:00 - MST 1930 Nov 16
- -8:00 - PST 1942 Apr
+ -8:00 - PST 1942 Apr 24
-7:00 - MST 1949 Jan 14
-8:00 BajaN P%sT 1976
-8:00 US P%sT 1996
===================================================================
RCS file: RCS/europe,v
retrieving revision 2000.4
retrieving revision 2000.4.0.1
diff -pu -r2000.4 -r2000.4.0.1
--- europe 2000/03/14 14:38:50 2000.4
+++ europe 2000/07/27 17:08:27 2000.4.0.1
@@ -131,6 +131,10 @@
# A bill was drafted in 1909 and introduced in Parliament several times,
# but it met with ridicule and opposition, especially from farming interests.
# One-hour Summer Time was eventually adopted as a wartime measure in 1916.
+# See:
+# <a href="http://www.the-times.co.uk/news/pages/tim/2000/05/18/x-timcrtcrt01011.html">
+# Summer Time Arrives Early, The Times (2000-05-18)
+# </a>
# From Paul Eggert (1996-09-03):
# The OED Supplement says that the English originally said ``Daylight Saving''
@@ -1856,7 +1860,8 @@ Zone Europe/Simferopol 2:16:24 - LMT 188
3:00 1:00 MSD 1996 Oct 27 3:00s
# IATA SSIM (1997-09) says Crimea switched to EET/EEST.
# Assume it happened in March by not changing the clocks.
- 3:00 Russia MSK/MSD 1997 Mar lastSun 1:00u
+ 3:00 Russia MSK/MSD 1997
+ 3:00 - MSK 1997 Mar lastSun 1:00u
2:00 EU EE%sT
# Yugoslavia
===================================================================
RCS file: RCS/asia,v
retrieving revision 2000.3
retrieving revision 2000.3.0.1
diff -pu -r2000.3 -r2000.3.0.1
--- asia 2000/03/04 15:31:07 2000.3
+++ asia 2000/07/27 17:08:27 2000.3.0.1
@@ -370,9 +370,9 @@ Zone Asia/Jayapura 9:22:48 - LMT 1932 No
9:00 - JAYT
# Iran
-# From Paul Eggert (1999-09-27), following up a suggestion by Rich Wales:
+# From Paul Eggert (2000-06-12), following up a suggestion by Rich Wales:
# Ahmea Alavi in
-# <a href="http://tehran.stanford.edu/Iran_Lib/Calendar/taghveem.txt">
+# <a href="http://www.persia.org/Iran_Lib/Calendar/taghveem.txt">
# TAGHVEEM (1993-07-12)
# </a>
# writes ``Daylight saving time in Iran starts from the first day
@@ -385,12 +385,13 @@ Zone Asia/Jayapura 9:22:48 - LMT 1932 No
# 1993 03-21 03-21 09-23 09-23
# 1994 03-21 03-21 09-22!= 09-23
# 1995 03-21 03-21 09-22!= 09-23
-# 1996 03-21!= 03-20 09-21!= 09-22
-# 1997 03-21 03-21 09-21!= 09-23
+# 1996 03-21!= 03-20 09-22 09-22
+# 1997 03-22!= 03-21 09-22!= 09-23
# 1998 03-21 03-21 09-21!= 09-23
# 1999 03-22!= 03-21 09-22!= 09-23
# 2000 03-21!= 03-20 09-21!= 09-22
-# 2001 03-17!= 03-21 09-19!= 09-23
+# 2001 03-19!= 03-21 09-19!= 09-23
+# 2002 03-18!= 03-21 09-18!= 09-23
#
# Go with Alavi starting with 1992.
# I used Ed Reingold's cal-persia in GNU Emacs 19.34 to compute Persian dates.
@@ -455,7 +456,23 @@ Zone Asia/Tehran 3:25:44 - LMT 1916
4:00 Iran IR%sT 1979
3:30 Iran IR%sT
+
# Iraq
+#
+# From Jonathan Lennox <lennox at cs.columbia.edu> (2000-06-12):
+# An article in this week's Economist ("Inside the Saddam-free zone", p. 50 in
+# the U.S. edition) on the Iraqi Kurds contains a paragraph:
+# "The three northern provinces ... switched their clocks this spring and
+# are an hour ahead of Baghdad."
+#
+# But Rives McDow (2000-06-18) quotes a contact in Iraqi-Kurdistan as follows:
+# In the past, some Kurdish nationalists, as a protest to the Iraqi
+# Government, did not adhere to daylight saving time. They referred
+# to daylight saving as Saddam time. But, as of today, the time zone
+# in Iraqi-Kurdistan is on standard time with Baghdad, Iraq.
+#
+# So we'll ignore the Economist's claim.
+
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Iraq 1982 only - May 1 0:00 1:00 D
Rule Iraq 1982 1984 - Oct 1 0:00 0 S
@@ -526,7 +543,7 @@ Rule Zion 1988 only - Apr 9 0:00 1:00 D
Rule Zion 1988 only - Sep 3 0:00 0 S
# From Ephraim Silverberg <ephraim at cs.huji.ac.il>
-# (1997-03-04, 1998-03-16, 1998-12-28, and 2000-01-17):
+# (1997-03-04, 1998-03-16, 1998-12-28, 2000-01-17 and 2000-07-25):
# According to the Office of the Secretary General of the Ministry of
# Interior, there is NO set rule for Daylight-Savings/Standard time changes.
@@ -537,14 +554,19 @@ Rule Zion 1988 only - Sep 3 0:00 0 S
# Saturday night from midnight daylight savings time to 11 p.m. standard
# time. 1996 is an exception to this rule where the change back to standard
# time took place on Sunday night instead of Saturday night to avoid
-# conflicts with the Jewish New Year. Starting in 1999, the change to
-# daylight savings time will still be on a Friday morning but from
+# conflicts with the Jewish New Year. In 1999, the change to
+# daylight savings time was still on a Friday morning but from
# 2 a.m. IST to 3 a.m. IDT; furthermore, the change back to standard time
-# will now also be on a Friday morning from 2 a.m. IDT to 1 a.m. IST for
-# 1999 only. In the years from 2000 to 2002, the change back will be from
-# 2 a.m. IDT to 1 a.m. IST the morning after the Jewish festival of
-# Shmini Atzeret (i.e. the morning of the 23rd of Tishrei in the lunar
-# Hebrew calendar).
+# was also on a Friday morning from 2 a.m. IDT to 1 a.m. IST for
+# 1999 only. In the year 2000, the change to daylight savings time was
+# similar to 1999, but although the change back will be on a Friday, it
+# will take place from 1 a.m. IDT to midnight IST. Starting in 2001, all
+# changes to/from will take place at 1 a.m. old time, but now there is no
+# rule as to what day of the week it will take place in as the start date
+# (except in 2003) is the night after the Passover Seder (i.e. the eve
+# of the 16th of Nisan in the lunar Hebrew calendar) and the end date
+# (except in 2002) is three nights before Yom Kippur [Day of Atonement]
+# (the eve of the 7th of Tishrei in the lunar Hebrew calendar).
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 1989 only - Apr 30 0:00 1:00 D
@@ -592,29 +614,37 @@ Rule Zion 1998 only - Sep 6 0:00 0 S
Rule Zion 1999 only - Apr 2 2:00 1:00 D
Rule Zion 1999 only - Sep 3 2:00 0 S
-# Minister of Interior, Natan Sharansky, has announced the dates for
-# the years 2000-2002. However, sources inside the ministry have noted
-# that the end date of 2000 and both dates of 2001-2002 should be regarded
-# as tentative pending final approval.
+# The Knesset Interior Committee has changed the dates for 2000 for
+# the third time in just over a year and have set new dates for the
+# years 2001-2004 as well.
+#
+# The official announcement for the start date of 2000 can be viewed at:
+#
+# ftp://ftp.huji.ac.il/pub/tz/announcements/2000-start.ps.gz
#
-# The official announcement for the years 2000-2002 can be viewed at:
+# The official announcement for the end date of 2000 and the dates
+# for the years 2001-2004 can be viewed at:
#
-# ftp://ftp.huji.ac.il/pub/tz/announcements/2000-2002.ps.gz
+# ftp://ftp.huji.ac.il/pub/tz/announcements/2000-2004.ps.gz
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
Rule Zion 2000 only - Apr 14 2:00 1:00 D
-Rule Zion 2000 only - Oct 22 2:00 0 S
-Rule Zion 2001 only - Apr 6 2:00 1:00 D
-Rule Zion 2001 only - Oct 10 2:00 0 S
-Rule Zion 2002 only - Mar 29 2:00 1:00 D
-Rule Zion 2002 only - Sep 29 2:00 0 S
+Rule Zion 2000 only - Oct 6 1:00 0 S
+Rule Zion 2001 only - Apr 9 1:00 1:00 D
+Rule Zion 2001 only - Sep 24 1:00 0 S
+Rule Zion 2002 only - Mar 29 1:00 1:00 D
+Rule Zion 2002 only - Oct 7 1:00 0 S
+Rule Zion 2003 only - Mar 28 1:00 1:00 D
+Rule Zion 2003 only - Oct 3 1:00 0 S
+Rule Zion 2004 only - Apr 7 1:00 1:00 D
+Rule Zion 2004 only - Sep 22 1:00 0 S
-# From Paul Eggert (2000-01-17):
-# Here are guesses for rules after 2002.
+# From Paul Eggert (2000-07-25):
+# Here are guesses for rules after 2004.
# They are probably wrong, but they are more likely than no DST at all.
# Rule NAME FROM TO TYPE IN ON AT SAVE LETTER/S
-Rule Zion 2003 max - Mar Fri>=25 2:00 1:00 D
-Rule Zion 2003 max - Oct 1 2:00 0 S
+Rule Zion 2005 max - Apr 1 1:00 1:00 D
+Rule Zion 2005 max - Oct 1 1:00 0 S
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Asia/Jerusalem 2:20:56 - LMT 1880
===================================================================
RCS file: RCS/australasia,v
retrieving revision 2000.3
retrieving revision 2000.3.0.1
diff -pu -r2000.3 -r2000.3.0.1
--- australasia 2000/03/04 15:31:07 2000.3
+++ australasia 2000/07/27 17:08:27 2000.3.0.1
@@ -737,6 +737,9 @@ Zone Pacific/Wallis 12:15:20 - LMT 1901
# (Australia) and start daylight saving on the last Sunday in August in 2000
# instead of the first Sunday in October.
+# Sim Alam (2000-07-03) reported a legal citation for the 2000/2001 rules:
+# http://www.thelaw.tas.gov.au/fragview/42++1968+GS3A@EN+2000070300
+
# Victoria
# The rules for 1971 through 1991 were reported by George Shepherd
===================================================================
RCS file: RCS/tz-link.htm,v
retrieving revision 2000.3
retrieving revision 2000.3.0.1
diff -pu -r2000.3 -r2000.3.0.1
--- tz-link.htm 2000/03/04 15:31:09 2000.3
+++ tz-link.htm 2000/07/27 17:08:27 2000.3.0.1
@@ -36,6 +36,9 @@ the code is in the file <samp>tzcode<var
where <samp><var>C</var></samp> is the code's version;
similarly, the data are in <samp>tzdata<var>D</var>.tar.gz</samp>,
where <samp><var>D</var></samp> is the data's version.
+The code lets you compile the text data into time zone files, one for
+each location. It also lets you read a compiled time zone file and
+interpret time stamps for that location.
<P>
The data are by no means authoritative. If you find errors, please
send changes to the <A HREF="mailto:tz at elsie.nci.nih.gov">time zone
@@ -46,12 +49,6 @@ HREF="ftp://elsie.nci.nih.gov/pub/tzarch
messages</A> (in <A HREF="http://www.gzip.org/">gzip</A> compressed
format).
<P>
-The <A HREF="http://www.gnu.org/software/libc/">GNU C Library</A>
-has an independent, thread-safe implementation of
-a time zone file reader that is compatible with <samp>tz</samp>.
-This library is freely available under the GNU Library General Public License,
-and is widely used in GNU/Linux systems.
-<P>
The Web has several other sources for time zone and daylight saving time data.
Here are some recent links that may be of interest.
<H2>Web pages using recent versions of the <samp>tz</samp> database</H2>
@@ -73,6 +70,19 @@ zone converter</A> is a multilingual int
is a web interface to a time zone database derived from
<samp>tz</samp>'s.
</UL>
+<H2>Other time zone file readers</H2>
+<UL>
+<LI>The <A HREF="http://www.gnu.org/software/libc/">GNU C Library</A>
+has an independent, thread-safe implementation of
+a time zone file reader that is compatible with <samp>tz</samp>.
+This library is freely available under the
+<A HREF="http://www.gnu.org/copyleft/lesser.html">
+GNU Lesser General Public License (LGPL)</A>,
+and is widely used in GNU/Linux systems.
+<LI><A HREF="http://www.bmsi.com/java/#TZ">ZoneInfo.java</A>
+is a time zone file reader written in Java.
+It is freely available under the GNU LGPL.
+</UL>
<H2>Other <SAMP>tz</SAMP>-based time zone conversion software</H2>
<UL>
<LI><A
@@ -85,9 +95,10 @@ Microsoft Windows 95/98/NT4 program.
<H2>Other time zone databases</H2>
<UL>
<LI><A HREF="http://www.astro.ch/atlas/">Astrology / Astrologie ->
-Astrodienst Atlas Database</A> is Astrodienst's Web version of <A
-HREF="http://astrocom.com/books/xrefa.htm#SHANKS">Shanks's
-excellent time zone history atlases</A> published by <A
+Astrodienst Atlas Database</A> is Astrodienst's Web version of Shanks's
+excellent time zone history atlases published in both <A
+HREF="http://astrocom.com/software/ACS_PC_Atlas.htm">computer</A> and <A
+HREF="http://astrocom.com/books/xrefa.htm#SHANKS">book</A> form by <A
HREF="http://astrocom.com/">Astro Communications Services</A>.
<LI><A HREF="http://worldtime.com/">WORLDTIME: interactive atlas,
time info, public holidays</A>
@@ -174,6 +185,14 @@ briefly explains interplanetary space fl
of IERS</A> contains official publications of the
International Earth Rotation Service, the committee that decides
when leap seconds occur.
+<LI>The <A
+HREF="http://clockdev.usno.navy.mil/archives/leapsecs.html">Leap
+Second Discussion List</A> covers <A
+HREF="http://www.gisdevelopment.net/reference/scie/s_t_41_50.htm#47">McCarthy
+and Klepczynski's proposal to remove leap seconds</A>, currently
+being studied by a <A
+HREF="http://www.intec.rug.ac.be/Research/Projects/ursi/Commissions.html">URSI
+Commission J</A> working group.
</UL>
<H2>Time notation</H2>
<UL>
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