utcOffset

const utcOffset: RegExp = /^[+-](?:[01][0-9]|2[0-3]):[0-5][0-9](?::[0-5][0-9])?$/;

RegExp matching an ISO 8601 UTC offset in the extended form GMT’s offset-instant pair stores: ±HH:MM, optionally ±HH:MM:SS.

Examples

import { utcOffset } from "@northguild/gmt";

utcOffset.test("-04:00") // true
utcOffset.test("+05:45") // true
utcOffset.test("-00:44:30") // true (Africa/Monrovia before 1972)
utcOffset.test("Z") // false (a designator, not an offset)
utcOffset.test("-0400") // false (basic format)
utcOffset.test("+24:00") // false (out of range)

Source

regex/utc-offset.ts