From: Sylvestre Ledru <sylvestre@debian.org>
Date: Mon, 1 Jun 2026 18:00:00 +0000 (+0200)
Subject: tests: date: check fixed offset is anchored before relative items
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=56ed0d516e53245cf49e641a1dc20ba80ab94f07;p=thirdparty%2Fcoreutils.git

tests: date: check fixed offset is anchored before relative items

A fixed-offset keyword such as 'UTC' must anchor the instant before
relative items are applied, so that '1970-01-01 UTC N seconds' is
exactly N seconds past the epoch even when the local zone observes
DST between the epoch and the result.

* tests/date/date-tz.sh: Add a relative-seconds-across-DST case.
https://github.com/coreutils/coreutils/pull/275
---

diff --git a/tests/date/date-tz.sh b/tests/date/date-tz.sh
index 0fd8ac16a6..fb8b657801 100755
--- a/tests/date/date-tz.sh
+++ b/tests/date/date-tz.sh
@@ -29,4 +29,14 @@ case $? in
   *) grep '^date: invalid date' err || fail=1 ;;
 esac
 
+# A fixed-offset keyword (here 'UTC') anchors the instant before relative
+# items are applied.  With a DST-observing zone the epoch base is in winter
+# while the result lands in summer, so adding the seconds must not pick up the
+# DST hour: '1970-01-01 UTC N seconds' is always exactly N seconds past the
+# epoch, regardless of TZ.
+secs=1780318971
+TZ='Europe/Berlin' date -d "1970-01-01 UTC $secs seconds" +%s > out || fail=1
+echo "$secs" > exp
+compare exp out || fail=1
+
 Exit $fail