SQL-DATABASE ERROR

Database error in pd Script: Invalid SQL: insert into pd_bewertung ( iddomain, bewertung, ip, zeit ) values ( '2162', '2', '38.107.191.86', '' )
mysql error: Incorrect integer value: '' for column 'zeit' at row 1
mysql error number: 1366
Date: 11.09.2010 @ 01:54
Script: /bewerten.php?action=bewerten&value=2&id=2162
Referer: