From 082787996c876e1a2db2b2ec6b784069e0a4e145 Mon Sep 17 00:00:00 2001
From: Jim Meyering <jim@meyering.net>
Date: Wed, 14 Oct 1998 21:27:52 +0000
Subject: [PATCH] Use the more portable "TZ=PST8PDT,M4.1.0,M10.5.0" instead of
 "TZ=America/Vancouver".  From Paul Eggert.

---
 m4/mktime.m4 | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/m4/mktime.m4 b/m4/mktime.m4
index 841e370..8d89b33 100644
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -50,7 +50,12 @@ spring_forward_gap ()
 {
   /* glibc (up to about 1998-10-07) failed this test) */
   struct tm tm;
-  putenv ("TZ=America/Vancouver");
+
+  /* Use the portable POSIX.1 specification "TZ=PST8PDT,M4.1.0,M10.5.0"
+     instead of "TZ=America/Vancouver" in order to detect the bug even
+     on systems that don't support the Olson extension, or don't have the
+     full zoneinfo tables installed.  */
+  putenv ("TZ=PST8PDT,M4.1.0,M10.5.0");
   tm.tm_year = 98;
   tm.tm_mon = 3;
   tm.tm_mday = 5;
-- 
2.7.4