Temporal.PlainDateTime.prototype.dayOfYear

Limited availability

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

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The dayOfYear accessor property of Temporal.PlainDateTime instances returns a positive integer representing the 1-based day index in the year of this date. The first day of this year is 1, and the last day is the daysInYear. It is calendar-dependent.

The set accessor of dayOfYear is undefined. You cannot change this property directly. To create a new Temporal.PlainDateTime object with the desired new dayOfYear value, use the add() or subtract() method with the appropriate number of days.

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