When stdoff is used for judgment, the value of stdoff is incorrect when it is switched from the rearguard mode to the vanguard mode. The value should be 1:00, but the actual value is 0:00. Test steps: 1. make VERSION=2026b ZFLAGS="-b fat" tzdata2026b-rearguard.tar.gz.t 2. tar xvf tzdata2026b-rearguard.tar.gz 3. make DATAFORM=vanguard all vanguard.zi: # Zone NAME STDOFF RULES FORMAT [UNTIL] Zone Africa/Casablanca -0:30:20 - LMT 1913 Oct 26 0:00 Morocco %z 1984 Mar 16 1:00 - %z 1986 0:00 Morocco %z 2018 Oct 28 3:00 0:00 Morocco %z 2026 Sep 20 2:00 0:00 - %z