The daysInYear accessor property of Temporal.PlainDate instances returns a positive integer representing the number of days in the year of this date. It is calendar-dependent.

For the ISO 8601 calendar, this is 365, or 366 in a leap year. In other calendar systems, it likely differs, especially in non-solar calendars.

The set accessor of daysInWeek is undefined. You cannot change this property directly.

Examples

Using daysInYear

const date = Temporal.PlainDate.from("2021-07-01");
console.log(date.daysInYear); // 365

const date2 = Temporal.PlainDate.from("2020-07-01");
console.log(date2.daysInYear); // 366; 2020 is a leap year

const date3 = Temporal.PlainDate.from("2021-07-01[u-ca=chinese]");
console.log(date3.daysInYear); // 354

const date4 = Temporal.PlainDate.from("2023-07-01[u-ca=chinese]");
console.log(date4.daysInYear); // 384; 2023 is a Chinese leap year

Specifications

Browser compatibility

See also

• Temporal.PlainDate
• Temporal.PlainDate.prototype.with()
• Temporal.PlainDate.prototype.add()
• Temporal.PlainDate.prototype.subtract()
• Temporal.PlainDate.prototype.year
• Temporal.PlainDate.prototype.dayOfYear
• Temporal.PlainDate.prototype.daysInMonth
• Temporal.PlainDate.prototype.daysInWeek