v0.9.0

Highlights

• Native IANA timezones backed by ICU, including historical offsets and daylight saving transitions.
• fold, ambiguous(), and imaginary() for repeated and missing local times.
• Calendar shifts preserve wall time; hours and smaller shifts and TimeDelta arithmetic use elapsed time.
• English, Simplified Chinese, and Traditional Chinese formatting, parsing, humanization, and dehumanization.
• UTF-8 literals in token formats and strftime, with localized month, weekday, and AM/PM text.
• Lazy ranges across DST transitions and correct arithmetic at calendar limits.

Runtime and migration

Named and local timezones require ICU. macOS includes it; on Debian/Ubuntu install libicu-dev. The Conda recipe includes the runtime dependency. UTC and fixed-offset operations do not load ICU. Timezone rules follow the selected ICU data version.

See the migration guide, timezone guide, and relative time guide.

Validation and downloads

119 test functions and 6,000 fixed-seed property samples cover core APIs, DST folds and gaps, half-hour transitions, skipped dates, historical and negative timestamps, calendar limits, and localized round trips. CI also runs 400 deterministic behavioral checks. Expanded regression tests fixed malformed Unicode crashes, invalid timestamp acceptance, and reversed spans within one calendar frame.

See the testing guide for commands and current tooling limits. Test counts are not line or branch coverage.

Archives support Mojo 1.0.0 and 1.1.0 on Linux x86-64, Linux ARM64, and macOS ARM64. Choose the archive matching your compiler and platform; verify it using SHA256SUMS. English and Chinese documentation builds are verified separately.