ADDDATE(expr,days) : ADDDATE « Date Time Functions « MySQL Tutorial

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

MySQL treats the second argument as an integer number of days to be added to expr.

mysql>
mysql> SELECT ADDDATE('1998-01-02', 31);
+---------------------------+
| ADDDATE('1998-01-02', 31) |
+---------------------------+
| 1998-02-02                |
+---------------------------+
1 row in set (0.00 sec)

mysql>