gistfile1.txt

mysql56> SET sql_mode= '';
Query OK, 0 rows affected (0.00 sec)

mysql56> INSERT INTO t1 VALUES ('2012-02-30');
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql56> SHOW WARNINGS;
+---------+------+---------------------------------------------+
| Level   | Code | Message                                     |
+---------+------+---------------------------------------------+
| Warning | 1264 | Out of range value for column 'dt' at row 1 |
+---------+------+---------------------------------------------+
1 row in set (0.01 sec)

mysql56>
mysql56> SET sql_mode= 'STRICT_TRANS_TABLES';
Query OK, 0 rows affected (0.00 sec)

mysql56>
mysql56> INSERT INTO t1 VALUES ('2012-02-30');
ERROR 1292 (22007): Incorrect datetime value: '2012-02-30' for column 'dt' at row 1

mysql56> SET sql_mode= CONCAT_WS(',', @@sql_mode, 'ALLOW_INVALID_DATES');
Query OK, 0 rows affected (0.00 sec)

mysql56>
mysql56> SELECT @@sql_mode;
+-----------------------------------------+
| @@sql_mode                              |
+-----------------------------------------+
| STRICT_TRANS_TABLES,ALLOW_INVALID_DATES |
+-----------------------------------------+
1 row in set (0.00 sec)

mysql56>
mysql56> INSERT INTO t1 VALUES ('2012-02-30');
Query OK, 1 row affected (0.01 sec)