Landing: 2b5e55eea69a
Project / Subsystem
gcc / libstdc++
Date
2026-05-12
Author
Álvaro Begué
Commit
2b5e55eea69acbc6e46fa3463164e62bcc436e0d
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- libstdc++
- patch_id
- —
- commit_hash
- 2b5e55eea69acbc6e46fa3463164e62bcc436e0d
- source_type
- github
- headline
- libstdc++: Support ON-format DAY in Zone UNTIL field [PR124852]
- tldr
- The libstdc++ now correctly parses complex day specifications in timezone definitions, fixing misinterpretations of historical dates.
- author
- Álvaro Begué
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • libstdc++
- • timezone
- • tzdata
- • bugfix
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-12T00:00:00.000Z
The libstdc++‘s timezone database parser now supports extended day-of-month formats (e.g., lastSun, Sun>=8) in the UNTIL field of Zone lines. Previously, the parser only accepted plain day-of-month integers, leading to misinterpretations of dates in certain timezones like Europe/Simferopol. This commit rectifies this by implementing a more robust parser and introducing a new test case to ensure correct handling of these formats.