The nanosecond accessor property of Temporal.PlainDateTime instances returns an integer from 0 to 999 representing the nanosecond (10-9 second) component of this time.
The set accessor of nanosecond is undefined. You cannot change this property directly. Use the with() method to create a new Temporal.PlainDateTime object with the desired new value.
For general information and more examples, see Temporal.PlainTime.prototype.nanosecond.
const dt = Temporal.PlainDateTime.from("2021-07-01T12:34:56.123456789");
console.log(dt.nanosecond); // 789Temporal.PlainDateTimeTemporal.PlainDateTime.prototype.with()Temporal.PlainDateTime.prototype.add()Temporal.PlainDateTime.prototype.subtract()Temporal.PlainDateTime.prototype.secondTemporal.PlainDateTime.prototype.millisecondTemporal.PlainDateTime.prototype.microsecondTemporal.PlainTime.prototype.nanosecond