isValidUtc

Signature

isValidUtc(value: string): boolean

Return true when the provided string is a valid ISO 8601 UTC datetime.

• The part before the first annotation must match utcDateTime (<date>T<time>Z): ISO 8601 extended format with an upper-case Z, so z, a t or space separator and basic format fail.
• Reads RFC 9557 annotations as Temporal.Instant.from does: elective ones ([foo=bar]), a time zone annotation and a calendar annotation are ignored (an instant has neither), and an unknown critical one ([!foo=bar]) is rejected.
• Accepts four forms beyond the timestamp shape YYYY-MM-DDTHH:MM:SS[.f]Z: a time without seconds, a comma before the fraction, an expanded ±YYYYYY year and RFC 9557 annotations. For the plain RFC 3339 spelling that readers other than Temporal expect, use isValidUtcTimestamp, which is false for all four.
• Rejects leap seconds (e.g., “2024-12-31T23:59:60Z”).
• Uses Temporal.Instant.from for validation.
• Requires a time component — date-only strings (“2024-01-01Z”) are rejected.

Parameters

Parameter	Type	Description
value	string	input UTC datetime string (ISO 8601)

Returns

boolean indicating whether the input is a valid UTC datetime

Examples

import { isValidUtc } from "@northguild/gmt/utc/validate";

isValidUtc("2024-03-17T14:30:45Z") // true

value

output

 

Source

utc/validate/isValidUtc.ts