An object with year, month, and day properties that are numbers, integers and valid range Valid ranges are from 1/1/0000 to 12/31/9999
true if the value is a valid DateOnly object with valid year, month, and day It checks if the month is between 1 and 12, and the day is between 1 and the number of days in the month handling leap years
Check if the given value is a valid DateOnly object.