Mysql find last friday last month---GOOD.

SET @GETLASTM=LAST_DAY('2013-08-01' - INTERVAL 1 MONTH);
SELECT DATE_FORMAT(LAST_DAY(@GETLASTM) - ((7 + WEEKDAY(LAST_DAY(@GETLASTM)) - 4) % 7), '%Y-%m-%d') last_friday;