QUARTER(date) returns the quarter of the year for date, in the range 1 to 4. : QUARTER « Date Time Functions « MySQL Tutorial

1. MySQL Tutorial
2. Date Time Functions
3. QUARTER

mysql>
mysql> SELECT QUARTER('99-04-01');
+---------------------+
| QUARTER('99-04-01') |
+---------------------+
|                   2 |
+---------------------+
1 row in set (0.00 sec)

mysql>