Extract the month. This function returns the month portion of a date as a number from 1 (January) to 12 (December).
SELECT MONTH('2019-01-03');
+---------------------+
| MONTH('2019-01-03') |
+---------------------+
| 1 |
+---------------------+
SELECT MONTH('2019-00-03');
+---------------------+
| MONTH('2019-00-03') |
+---------------------+
| 0 |
+---------------------+