mysql> select adddate(now(), 1); +---------------------+ | adddate(now(), 1) | +---------------------+ | 2014-05-27 23:19:29 | +---------------------+ 1 row in set (0.00 sec) mysql> select adddate(now(), -1); +---------------------+ | adddate(now(), -1) | +---------------------+ | 2014-05-25 23:19:36 | +---------------------+ 1 row in set (0.00 sec)