Clock In Function for Same/Next Day

manual_time.php

//Part of the system allows an admin to change the clock in/out times if any errors happen
//Once updated it needs to work out the difference between the in and out for other use.
            $end = strtotime($details[1]);
            $end_mid = strtotime('23:59:59');
            //dates & times of in & out - assume the same day for both
            $comDTin = date('Y-m-d H:i:s', strtotime("$date $time_in"));
            $comDTin_raw = strtotime($comDTin);
            $comDTout = date('Y-m-d H:i:s', strtotime("$date $end_raw"));
            $comDTout_raw = strtotime($comDTout);
            //the out time can NEVER be less than the in time.  If it is less that means the user clocked out the following day!
               if ($comDTout_raw < $comDTin_raw) {
                   //Next Day Clock Out
                    $new_date = date('Y-m-d',strtotime($date . "+1 day"));
                }else{
                    //Same Day Clock Out
                    $new_date = $details[3];
                }
                if ($date==$new_date){ //Same Day
                    $dif = $end-$start;
                    $difmin = round($dif/60);
                    
                }else{ //Next Day
                    $midnight = strtotime('00:01:00');
                    $dif = $end_mid-$start;
                    $dif2 = $end-$midnight;
                    $difmin = round(($dif+$dif2)/60);
                }

time.php

//This one presented a real challange at first because working with dates & times is a nightmare.
//Get Last clockin where there is not clock out value
    $timecheck = mysql_query("SELECT * FROM timekeep WHERE user = '$user' and timediff IS NULL order by date DESC limit 1");
    $details = mysql_fetch_row($timecheck);
    $date_in = $details[2];  //Clock In Date
    $start = strtotime($details[3]); //Clock In Time
    $end = strtotime($time);  //Current TIme
    if ($date_in==$date){ //Same day clock out $date = current date
        $dif = $end-$start;
        $difmin = round($dif/60);
    }else{ //Next day clock out
        $end_mid = strtotime('23:59:59'); //End of Day Time
        $midnight = strtotime('00:01:00'); //Start of Day Time
        $dif = $end_mid-$start; //First difference between Clock In & Midnight
        $dif2 = $end-$midnight; //Second difference between Clock Out & 1 min past midnight
        $difmin = round(($dif+$dif2)/60);
    }