FROM_DAYS(N): Given a day number N, returns a DATE value : FROM_DAYS « Date Time Functions « MySQL Tutorial

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

mysql>
mysql> SELECT FROM_DAYS(729669);
+-------------------+
| FROM_DAYS(729669) |
+-------------------+
| 1997-10-07        |
+-------------------+
1 row in set (0.00 sec)

mysql>