Syntax
DATEDIFF(date1, date2)
Purpose
DATEDIFF() returns the number of months between date1 and date2.
Only the date part of the parameter is used in the calculation. The time part is ignored.
Examples
obclient> SELECT DATEDIFF('2015-06-19','1994-12-17');
+-------------------------------------+
| DATEDIFF('2015-06-19','1994-12-17') |
+-------------------------------------+
| 7489 |
+-------------------------------------+
1 row in set