mysql date question

I have a field in mysql as shown by describe contract;

| length_start         | date                | YES  |     | NULL    |                |

Which stores it in the mysql format of YYYY-MM-DD. However, I need the output of my select statement to show it in MM-DD-YYYY format. I can select it to see the date in the field: select length_start from contract where user_id = 1; +--------------+ | length_start | +--------------+ | 2006-01-12 | +--------------+ 1 row in set (0.00 sec) so then I do my date_format() select statement, but it returns a NULL value. Why? select date_format('contract.length_start', '%m-%d-%Y') as length_start from contract where user_id = 1; +--------------+ | length_start | +--------------+

| NULL         |

+--------------+ 1 row in set, 1 warning (0.00 sec)