23 lines
720 B
TypeScript
23 lines
720 B
TypeScript
export function getTimezones(includeUtc = true) {
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const possibleTimezones = Intl.supportedValuesOf("timeZone").sort();
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if (includeUtc) {
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possibleTimezones.unshift("UTC");
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}
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return possibleTimezones;
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}
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/**
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* Whether the runtime can resolve this IANA timezone. Prefer this over checking membership
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* in `Intl.supportedValuesOf("timeZone")`, which lists only canonical ids and omits zones
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* browsers legitimately report (e.g. "UTC", "Etc/UTC", "Asia/Kolkata") — rejecting those
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* would leave a client's stored timezone stale.
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*/
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export function isValidTimeZone(timeZone: string): boolean {
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try {
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new Intl.DateTimeFormat("en-US", { timeZone });
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return true;
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} catch {
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return false;
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}
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}
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