Temporal.PlainYearMonth.prototype.era

The era accessor property of Temporal.PlainYearMonth instances returns a calendar-specific lowercase string representing the era of this year-month, or undefined if the calendar does not use eras (e.g. ISO 8601). era and eraYear together uniquely identify a year in a calendar, in the same way that year does. It is calendar-dependent.

The set accessor of era is undefined. You cannot change this property directly. Use the with() method to create a new Temporal.PlainYearMonth object with the desired new value.

For general information and more examples, see Temporal.PlainDate.prototype.era.

const ym = Temporal.PlainYearMonth.from("2021-07"); // ISO 8601 calendar
console.log(ym.era); // undefined

const ym2 = Temporal.PlainYearMonth.from("2021-07-01[u-ca=gregory]");
console.log(ym2.era); // gregory