From d582a6e3b650d3f66ac43968696ee94b53166f1a Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Thu, 2 Mar 2017 01:30:19 -0800
Subject: [PROPOSED] Fix Liberia 1972 transition and pre-1972 abbr
* NEWS: Document this.
* africa (Africa/Monrovia): The 1972 transition was on January 7,
not May 1. (Shanks was wrong again! and Howse was right.)
Use MMT for pre-1972 abbreviation.
---
NEWS | 10 ++++++++++
africa | 25 ++++++++++++++++---------
2 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/NEWS b/NEWS
index 306685a..b3917d0 100644
--- a/NEWS
+++ b/NEWS
@@ -1,5 +1,15 @@
News for the tz database
+Unreleased, experimental changes
+
+ Changes to past time stamps
+
+ Liberia changed from -004430 to +00 on 1972-01-07, not 1972-05-01.
+
+ Use "MMT" to abbreviate Liberia's time zone before 1972, as "-004430"
+ is one byte over the POSIX limit. (Problem reported by Derick Rethans.)
+
+
Release 2017a - 2017-02-28 00:05:36 -0800
Briefly: Southern Chile moves from -04/-03 to -03, and Mongolia
diff --git a/africa b/africa
index e617396..dcc20b9 100644
--- a/africa
+++ b/africa
@@ -420,18 +420,25 @@ Link Africa/Nairobi Indian/Mayotte
# See Africa/Johannesburg.
# Liberia
-# From Paul Eggert (2006-03-22):
-# In 1972 Liberia was the last country to switch
-# from a UTC offset that was not a multiple of 15 or 20 minutes.
-# Howse reports that it was in honor of their president's birthday.
-# Shank & Pottenger report the date as May 1, whereas Howse reports Jan;
-# go with Shanks & Pottenger.
-# For Liberia before 1972, Shanks & Pottenger report -0:44, whereas Howse and
-# Whitman each report -0:44:30; go with the more precise figure.
+#
+# From Paul Eggert (2017-03-02):
+#
+# The Nautical Almanac for the Year 1970, p 264, is the source for -0:44:30.
+#
+# In 1972 Liberia was the last country to switch from a UTC offset
+# that was not a multiple of 15 or 20 minutes. The 1972 change was on
+# 1972-01-07, according to an entry dated 1972-01-04 on p 330 of:
+# Presidential Papers: First year of the administration of
+# President William R. Tolbert, Jr., July 23, 1971-July 31, 1972.
+# Monrovia: Executive Mansion.
+#
+# Use the abbreviation "MMT" before 1972, as the more-accurate numeric
+# abbreviation "-004430" would be one byte over the POSIX limit.
+#
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Africa/Monrovia -0:43:08 - LMT 1882
-0:43:08 - MMT 1919 Mar # Monrovia Mean Time
- -0:44:30 - -004430 1972 May
+ -0:44:30 - MMT 1972 Jan 7 # approximately MMT
0:00 - GMT
###############################################################################
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2.7.4