Day
The Day function returns the day(1-31) of the month given a date value or a serial day number.
Usage:
= Day(<date_or_number>)
Example with a date value:
/* returns 15 */
var myDate = Date(2005, 6, 15);
= Day(myDate);
Or with a serial day number:
/* returns 15 for 15-June-2005 */
= Day(38518);
Or with a serial day number:
/* returns 30 for 30-December-1899 */
= Day(0);