Installation

npm install @cosyte/dates

or pnpm add @cosyte/dates.

Requirements

• Node.js 22 or later, tested on 22, 24, and 26.
• ESM only. The package ships no CommonJS build, so load it with import; require() will not load it.

Dependencies

One runtime dependency, temporal-polyfill, because Temporal.PlainDate is the only widely available type that holds a calendar date with no time of day and no zone. Temporal is re-exported from this package, so you work with the same objects rather than installing a second copy: two Temporal implementations do not share instanceof.

import { Temporal } from "@cosyte/dates";

Check the install

import { toISO, precisionOf } from "@cosyte/dates";

console.log(toISO({ year: 1988, month: 5 }), precisionOf({ year: 1988, month: 5 }));
// 1988-05 month

If that prints, the install is good. Head to the Quickstart.