If you are working with Microsoft MSSQL and its "Sqlsrv"-Driver with Zend Framework2 and Doctrine2 you will have some troubles with the "datetime" and "date" types in Doctrine2. The MSSQL-Server doesn't accept the defined standard format "Y-m-D H:i:s" or "Y-m-D" in Doctrine2.
To avoid problems with the format use the ZF2Doctrine2SqlsrvTypes module which integrates the two new DBAL Types SqlsrvDatetime and SqlsrvDate.
After installing the module via composer just replace the types in your doctrine2 notation from "datetime" to "SqlsrvDatetime" and from "date" to "SqlsrvDate".
Just add the following dependency to your composer.json file and add the module "ZF2Doctrine2SqlsrvTypes" to your modules list in the application.config.php.
{
"require": {
"maegnes/zf2doctrine2sqlsrv": "dev-master"
}
}