DAY

Description: Returns the number of the day from a specified date. For example, =DAY("15-Apr-2011") returns 15.

Syntax: DAY(Serial_number)

Serial_number is the date of the day you are trying to find. Dates should be entered by using the DATE function, or as results of other formulas or functions. For example, use DATE(2011,5,23) for the 23rd day of May, 2011. Problems can occur if dates are entered as text. For more information, see the NOW function.

Remarks:

The software stores dates as sequential serial numbers so they can be used in calculations. January 1, 1900 is serial number 1, and January 1, 2011 is serial number 40544 because it is 40,544 days after January 1, 1900. For more information, see the NOW function.
Values returned by the YEAR, MONTH and DAY functions will be Gregorian values regardless of the display format for the supplied date value. For example, if the display format of the supplied date is Hijri (Hijri calendar: The lunar calendar that is used in Islamic regions.), the returned values for the YEAR, MONTH and DAY functions will be values associated with the equivalent Gregorian date.

Example: