MySQL Tutorial/Date Time Functions/PERIOD DIFF

PERIOD_DIFF(P1,P2) returns the number of months between periods P1 and P2.

P1 and P2 should be in the format YYMM or YYYYMM.

The period arguments P1 and P2 are not date values.

mysql>
mysql> SELECT PERIOD_DIFF(9803,199803);
+--------------------------+
| PERIOD_DIFF(9803,199803) |
+--------------------------+
|                        0 |
+--------------------------+
1 row in set (0.00 sec)
mysql>