https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124554
--- Comment #11 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <[email protected]>: https://gcc.gnu.org/g:663e5ade184813a8a5f6f76b873c3e212c1e8e75 commit r16-8167-g663e5ade184813a8a5f6f76b873c3e212c1e8e75 Author: Jonathan Wakely <[email protected]> Date: Sat Mar 14 10:32:11 2026 +0000 libstdc++: Fix time zone transitions for Rule changes during DST [PR116110] The Australia/Broken_Hill example in PR libstdc++/116110 demonstrates a bug in the time zone code. The current code gives incorrect results when a zone changes from one named Rule to another during DST, e.g. the Broken_Hill time zone uses: 9:30 AN AC%sT 2000 9:30 AS AC%sT So the AS Rules take effect on 2000 Jan 1 which is during DST (which runs from October to March). The fix for this is to update info.offset and info.save when we find an active rule, instead of only updating the 'letters' variable. The new tests for Pacific/Kiritimati and Pacific/Apia have some FIXME comments. The UNTIL times of the zone changes are incorrectly interpreted as UTC not wall time (due to the main topic of Bug 116110), and the "24" time for the Pacific/Apia zone is incorrectly ignored so that the change happens 24h too early (due to Bug 124554). Those tests will need to be adjusted later when the bugs are fixed. libstdc++-v3/ChangeLog: PR libstdc++/116110 * src/c++20/tzdb.cc (time_zone::_M_get_sys_info): Update info.offset and info.save to values from the active rule. * testsuite/std/time/time_zone/116110.cc: New test. Reviewed-by: Tomasz KamiÅski <[email protected]>
