Temporal.PlainDate.prototype.year

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

The year accessor property of Temporal.PlainDate instances returns an integer representing the number of years of this date relative to the start of a calendar-specific epoch year. This property has the same function as the era/eraYear pair as a unique identifier of a year in a calendar. It is calendar-dependent.

Value

Usually year 1 is either the first year of the latest era or the ISO 8601 year 0001. Because year is relative to the start of the epoch year, not the epoch date, if the epoch is in the middle of the year (only known to happen for the japanese calendar), that year will have the same year value before and after the start date of the era (for the japanese calendar, year is the same as the ISO 8601 year).

All specified calendars have arithmetic years fully defined by the spec.

The following calendars have the same epoch year as ISO 8601: chinese, dangi, gregory, japanese, in which year: 1 corresponds to the ISO year 1.
The buddhist calendar uses the Buddhist epoch of 543 BCE, so year: 1 corresponds to the ISO year -542.
The coptic calendar uses the Coptic epoch of 284 CE, so year: 1 corresponds to the ISO year 284.
The ethioaa calendar uses the Anno Mundi epoch of 5493 BCE, so year: 1 corresponds to the ISO year -5492.
The ethiopic calendar uses the Ethiopic epoch of 8 CE, so year: 1 corresponds to the ISO year 8.
The hebrew calendar uses the Anno Mundi epoch of 3761 BCE, so year: 1 corresponds to the ISO year -3760.
The indian calendar uses the Śaka epoch of 79 CE, so year: 1 corresponds to the ISO year 79.
The following calendars use the Hijri epoch of 622 CE: islamic-civil, islamic-tbla, islamic-umalqura, persian, in which year: 1 corresponds to the ISO year 622.
The roc calendar uses the Minguo epoch of 1912 CE, so year: 1 corresponds to the ISO year 1912.

Note: For the chinese and dangi calendars, the CLDR data uses the Huangdi epoch of 2637 BCE by default, but Temporal defined it to use the ISO 8601 epoch for simplicity.

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

Examples

Using year

const date = Temporal.PlainDate.from("2021-07-01"); // ISO 8601 calendar
console.log(date.year); // 2021

const date2 = Temporal.PlainDate.from("-002021-07-01");
console.log(date2.year); // -2021

const date3 = Temporal.PlainDate.from("2021-07-01[u-ca=japanese]");
console.log(date3.year); // 2021; although the Japanese calendar uses eras,
// there's no obvious "default era", so the year is the same as the ISO year

const date4 = Temporal.PlainDate.from("2021-07-01[u-ca=hebrew]");
console.log(date4.year); // 5781; the Hebrew calendar uses the Anno Mundi epoch, which starts in 3761 BC