e99af31f____DataMapper_ORM___User_Guide__Parameter
[Rule] valid_date_group [Description] Returns FALSE if the property, grouped with other properties, is not a valid date. [Example] 'valid_date_group' => array('year' => 'property1', 'month' => 'property2', 'day' => 'property3') [Parameter] 
Yes
N o
Y e s
Validation : DataMapper ORM - User Guide
Parameter