v0.4.38

This release bring a ca. 20% improvement to the performance of the formatting code, and a convenient days_since method for the Weekday type.

Chrono 0.4.38 also removes the long deprecated rustc-serialize feature. Support for rustc-serialize will be soft-destabilized in the next Rust edition. Removing the feature will not break existing users of the feature; Cargo will just not update dependents that rely on it to newer versions of chrono.

In chrono 0.4.36 we made an accidental breaking change by switching to derive(Copy) for DateTime instead of a manual implementation. It is reverted in this release.

Removals

• Remove rustc-serialize feature (#1548, thanks @workingjubilee)

Additions

• Add Weekday::days_since (#1249, based on #216 by @clarfonthey)
• Add TimeDelta::checked_mul and TimeDelta::checked_div (#1565, thanks @Zomtir)

Fixes

• Return error when rounding with a zero duration (#1474, thanks @Dav1dde)
• Manually implement Copy for DateTime if offset is Copy (#1573)

Internal

• Inline test_encodable_json and test_decodable_json functions (#1550)
• CI: Reduce combinations in cargo hack check (#1553)
• Refactor formatting code (#1335)
• Optimize number formatting (#1558)
• Only package files needed for building and testing (#1554)

Thanks to all contributors on behalf of the chrono team, @djc and @pitdicker!