Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The withCalendar() method of Temporal.PlainDate instances returns a new Temporal.PlainDate object representing this date interpreted in the new calendar system. Because all Temporal objects are designed to be immutable, this method essentially functions as the setter for the date's calendarId property.
To replace the date component properties, use the with() method instead.