mysql> select now() + interval 2918472 day;
+------------------------------+
| now() + interval 2918472 day |
+------------------------------+
| 9999-12-31 16:14:03          |
+------------------------------+
1 row in set (0.00 sec)

mysql> select now() + interval 2918473 day;
+------------------------------+
| now() + interval 2918473 day |
+------------------------------+
| NULL                         |
+------------------------------+
1 row in set, 1 warning (0.00 sec)

Hehe.