CODE EXAMPLE FOR PHP

datetime confict function php

$timeExist = checkTimeConfict(strtotime($postStartTime),strtotime($postEndTime),strtotime($dbStartTime),strtotime($dbEndTime));
if($timeExist){ // NOT IN CONFICT
  $isTimeOverlap = 0;
}else{ // TIME OVERLAP 
  $isTimeOverlap = 1;
  break;
}


function checkTimeConfict($post_start_time1,$post_end_time1,$db_start_time2,$db_end_time2)
{
    $timeCheck;
    if(($post_end_time1 < $db_start_time2))
    {
        $timeCheck = true;
        return $timeCheck;
    }
    else if(($post_start_time1 > $db_start_time2) && ($post_start_time1 > $db_end_time2)) 
    {
        $timeCheck = true;
        return $timeCheck;
    }
    else
    {
        $timeCheck = false;
        return $timeCheck;
    }

}