# What changed in temporal-polyfill

> 9 changes in temporal-polyfill 1 from its official release notes, upgrade guides and advisories. Each one cited. Sources checked 2026-10-24. HTML: https://unstale.sh/npm/temporal-polyfill/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## temporal-polyfill 1

### Performance

- Tree-shakeable API imports are 27.30% smaller on average after minification and gzip. (1.0.5) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.5)

### Fixes and other changes

- Disallowed duration units now produce a clearer error, naming the invalid unit and the allowed range. (1.0.6) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.6)
- Fixes a load-time ReferenceError under ESM loaders that wrap modules, such as OpenTelemetry's import-in-the-middle. (1.0.6) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.6)
- Preserves transitions at epoch nanoseconds 0n instead of returning null in both class-based and tree-shakeable APIs. (1.0.5) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.5)
- Sub-hour difference functions preserve fractional precision and return positive zero for results that round to zero. (1.0.5) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.5)
- Improves parity with class-based APIs for year, month, week, and day differences, including rounding, validation, precision, and range handling. (1.0.5) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.5)
- Tree-shakeable helpers now use correct non-ISO calendar boundaries instead of mixing calendar year/month values with ISO fields. (1.0.5) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.5)
- The /full entrypoint now defers to native Temporal. (1.0.4) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.4)
- The tree-shakeable API is now CJS-friendly for require(esm). (1.0.4) — [release notes](https://github.com/fullcalendar/temporal-polyfill/releases/tag/temporal-polyfill%401.0.4)