MySQL:

DAYOFMONTH

Syntax:
DAYOFMONTH(date)

Returns the day of the month for date, in the range 1 to 31, or 0 for
dates such as '0000-00-00' or '2008-00-00' that have a zero day part.

Example

mysql> SELECT DAYOFMONTH('2007-02-03');
-> 3

bottom of page