The Temporal.Instant.fromEpochNanoseconds() static method creates a new Temporal.Instant object from the number of nanoseconds since the Unix epoch (midnight at the beginning of January 1, 1970, UTC).
To convert a Date object to a Temporal.Instant object, use Date.prototype.toTemporalInstant() instead.
Temporal.Instant.fromEpochNanoseconds(epochNanoseconds)epochNanosecondsA BigInt representing the number of nanoseconds since the Unix epoch.
A new Temporal.Instant object representing the instant in time specified by epochNanoseconds.
RangeErrorThrown if epochNanoseconds is not in the representable range, which is ±108 days, or about ±273,972.6 years, from the Unix epoch.
const instant = Temporal.Instant.fromEpochNanoseconds(0n);
console.log(instant.toString()); // 1970-01-01T00:00:00Z
const vostok1Liftoff =
Temporal.Instant.fromEpochNanoseconds(-275248380000000000n);
console.log(vostok1Liftoff.toString()); // 1961-04-12T06:07:00Z
const sts1Liftoff = Temporal.Instant.fromEpochNanoseconds(355924804000000000n);
console.log(sts1Liftoff.toString()); // 1981-04-12T12:00:04Z