Temporal Standards
A specification proposal and deployed browser support are separate things. Feature-detect Temporal and consult the current compatibility table before requiring it.
Where to run this
This example uses the JavaScript console playground. Select Run to execute it; the example does not run on this lesson page.
A practical example
if (typeof Temporal === "undefined") {
console.log("Temporal is not available in this runtime. Use a supporting browser or a reviewed local polyfill.");
} else {
console.log(typeof Temporal);
console.log(Temporal.PlainDate.from("2026-11-07").calendarId);
}
What happens
A supported runtime identifies Temporal and the ISO calendar.