// $p_hour_data['p_hour']=02:00:00
//$data['dapr_p_hour']=01:00:00
//answer is=01:00:00

$total_hour=((strtotime($p_hour_data['p_hour']))-(strtotime($data['dapr_p_hour'])));
echo $total_hour=gmdate("H:i:s", $total_hour);