Syntax
TIMESTAMPDIFF(unit, date1, date2)
Purpose
You can call this function to return the interval between two date and time values in the unit specified for unit. unit can only be an independent unit in DATE_ADD().
Examples
obclient> SELECT
TIMESTAMPDIFF(SECOND, NOW(), '2011-01-01 11:11:11'),
TIMESTAMPDIFF(DAY, '2011-01-01 11:11:11', NOW())
\G
*************************** 1. row ***************************
TIMESTAMPDIFF(SECOND, NOW(), '2011-01-01 11:11:11'): -231677498
TIMESTAMPDIFF(DAY, '2011-01-01 11:11:11', NOW()): 2681
1 row in set (0.00 sec)