Date.prototype.setFullYear()

The setFullYear() method of Date instances changes the year, month, and/or day of month for this date according to local time.

If you do not specify the monthValue and dateValue parameters, the same values as what are returned by getMonth() and getDate() are used.

If a parameter you specify is outside of the expected range, other parameters and the date information in the Date object are updated accordingly. For example, if you specify 15 for monthValue, the year is incremented by 1 (yearValue + 1), and 3 is used for the month.

Because setFullYear() operates on the local time, crossing a Daylight Saving Time (DST) boundary may result in a different elapsed time than expected. For example, if setting the date crosses a spring-forward transition (losing an hour), the difference in timestamps between the new and old date is one hour less than the nominal day difference multiplied by 24 hours. Conversely, crossing a fall-back transition (gaining an hour) result in an extra hour. If you need to adjust the date by a fixed amount of time, consider using setUTCFullYear() or setTime().

Syntax example: setFullYear(yearValue)