@date-fns/utc

The package provides Date extensions UTCDate and UTCDateMini that perform all calculations in UTC rather than the system time zone.

Using it makes [date-fns] operate in UTC but can be also used without it.

Installation

npm install @date-fns/utc --save

Usage

UTCDate and UTCDateMini have API identical to Date, but perform all calculations in UTC, which might be essential when calculating abstract date-time, i.e for rendering chart or calendar component:

import { UTCDate } from "@date-fns/utc";
import { addHours } from "date-fns";

// Given that the system time zone is America/Los_Angeles
// where DST happens at Sunday, 13 March 2022, 02:00:00

// Using system time zone will produce 03:00 instead of 02:00 because of DST:
const date = new Date(2022, 2, 13);
addHours(date, 2).toString();
//=> 'Sun Mar 13 2022 03:00:00 GMT-0700 (Pacific Daylight Time)'

// Using UTC will provide expected 02:00:
const utcDate = new UTCDate(2022, 2, 13);
addHours(utcDate, 2).toString();
//=> 'Sun Mar 13 2022 02:00:00 GMT+0000 (Coordinated Universal Time)'

Difference between UTCDate and UTCDateMini

Unlike UTCDateMini which implements only getters, setters, and getTimezoneOffset, UTCDate also provides formatter functions, mirroring all original Date functionality:

import { UTCDateMini, UTCDate } from "@date-fns/utc";

// UTCDateMini will format date-time in the system time zone:
new UTCDateMini(2022, 2, 13).toString();
//=> 'Sat Mar 12 2022 16:00:00 GMT-0800 (Pacific Standard Time)'

// UTCDate will format date-time in the UTC, like expected:
new UTCDate(2022, 2, 13).toString();
//=> 'Sun Mar 13 2022 00:00:00 GMT+0000 (Coordinated Universal Time)'

Even though UTCDate has a complete API, developers rarely use the formatter functions outside of debugging, so we recommend you pick the more lightweight UTCDateMini for internal use. However, in environments you don't control, i.e., when you expose the date from a library, using UTCDate will be a safer choice.

For instance, in date-fns locale functions (format, parse, etc.), we use UTCDateMini to ensure the minimal build size.

Changelog

See the changelog.

License

MIT © Sasha Koss