pytz is a Python historical timezone library that brings the IANA time zone database into Python, useful for accurate and cross platform timezone calculations. It is deprecated and may fail for dates starting in 2038, with updates continuing for legacy systems.
Project status
- Actively maintained, with recent GitHub activity and frequent updates, the latest upstream push on 2026-10-04 and subsequent update on 2026-10-04 (release_2026.5).
- Apparent update cadence is roughly monthly in 2026 (updates on 2026-10-04, 2026-09-24, then 2026-07-25, 2026-05-04, and 2026-03-03), suggesting an ongoing process of refreshing bundled tzdb and associated tooling.
AI summary generated
Recent updates
release_2026.5
release_2026.5 bumps pytz to OLSON tzdb version 2026e and updates the bundled tz database files. The underlying tz rules change most notably affects Manitoba and the America/Winnipeg zone around late 2026, which can alter offsets and abbreviations returned by pytz. CI metadata is also updated to add Python 3.14 and run more Python versions.
BreakingFeaturesrelease_2026.4
Release release_2026.4 updates the bundled Olson tzdata to 2026d and modifies pytz core behavior around timezone input validation and FixedOffset integration with BaseTzInfo. It also pulls in a large set of tzdb (and tz tool) source and data updates that can change timezone offsets and abbreviations for certain historical and future timestamps.
Securityrelease_2026.3.post1
This release appears to be a packaging version bump to 2026.3.post1, updating the exported pytz version string and the corresponding test expectations. The code diff also includes minor CI workflow changes and a comment typo fix, with no clear functional changes to timezone handling logic.
release_2026.3
Release release_2026.3 bumps pytz’s bundled timezone database from OLSON_VERSION 2026b to 2026c (VERSION 2026.3) and updates internal timezone parsing/localization logic. No publisher release notes were provided, so all behavior-affecting changes below are effectively undocumented in the release text.
release_2026.2
This release updates the pytz package version (OLSON_VERSION and VERSION constants) and refreshes bundled tz database data. It also updates the tz toolchain notes and makes multiple code changes in tz's zic compiler, primarily around signal handling robustness, plus fixes described in tz/NEWS for overflow and adversarial-input issues. No publisher release notes were provided for release_2026.2.
Securityrelease_2026.1.post1
This release bumps the pytz package version from 2026.1 to 2026.1.post1. The main code change is an update to how pytz locates and opens its zoneinfo resources, with additional CI and test harness adjustments for newer Python versions.
release_2026.1
No GitHub release notes were provided for release_2026.1. The code diff shows a pytz version bump (2025.2 to 2026.1, Olson database 2025b to 2026a) along with a large tz database (tzcode/tzdata) refresh that changes build defaults and core time conversion behavior, especially around leap seconds and obsolete POSIX rule handling.
BreakingSecurityFeaturesrelease_2025.2
release_2025.2 bumps pytz/Olson version identifiers and updates the bundled IANA tz database content (zone tables, zone definitions, and the zic compiler). The main functional impact is time zone data changes (Chile, Iran, and some documentation/citation updates), plus code changes in zic related to symlink creation and diagnostics.
release_2025.1
The publisher did not provide any release notes for release_2025.1. From the code diff, this release primarily bumps pytz to version 2025.1 and updates the bundled tz database to tzdb 2025a, including substantial tzcode source changes (not just data updates) and several build/check adjustments.
Featuresrelease_2024.2
Release release_2024.2 contains a version bump of pytz (2024.1 to 2024.2, Olson data 2024a to 2024b) and a large tzdb update. No release notes were provided by the publisher, so the only available change information comes from the code diff, which includes many timezone rule/data modifications and some build/code changes in the bundled tz tooling.
BreakingFeatures