im sending jquery date value and database cannot update the current format so i need php date conversion pls anyone suggest me

What format are you sending?

Use strtotime(), you can do it like this:

$date = date('Y-m-d', strtotime($_POST['date'])) . ' 00:00:00';

And use a datetime field, since the timestamp:

The TIMESTAMP data type is used for values that contain both date and time parts. TIMESTAMP has a range of '1970-01-01 00:00:01' UTC to '2038-01-19 03:14:07' UTC.