I want display GMT 0 todays data users timezone wise.

I want data from mysql according multiple timezone. I have a GMT 0 data in a database. In my application there are multiple users globally. So i want calls data according to user timezone wise.

I get data by GMT 0 timezone from database and then i convert that data into perticular users timezone. I want Arizona time zone mostly so it is GMT-7. When i get todays data user wise issue is that when GMT 0 and GMT-7 date is same result shows diffrent and if date is not same then result is correct

I attached my Codeigniter API code of get chart data of todays calls. So if you have any solution Your thoughts are very welcome.

 
 public function __construct()
 {
     date_default_timezone_set('UTC');
 }

 
 public function getChartNumberOfCalls($company_uuid,$timezoneid){
     if($_SERVER['REQUEST_METHOD']=='OPTIONS'){
         return json_encode('OK');
     }
     $request_body = file_get_contents('php://input');

     $filterhrs = $this->api_model->convert_to_GMT($startdate,1,$timezoneid);

     $currdate = $this->api_model->display_to_GMT(date('Y-m-d H:i:s'),1,$timezone1);
     $NumberOfCalls = $this->api_model->getChartNumberOfCalls($company_uuid,$currdate);

     $calls = array();
       $hrsarr = array();
       $keyhrsarr = array();
       foreach ($NumberOfCalls as $key => $value) {
         if($value['month']<10)
         $value['month'] ='0'.$value['month'];
         if($value['Hours']<10)
         $value['Hours'] ='0'.$value['Hours'];
         $convertdate = $value['year'].'-'.$value['month'].'-'.$value['day'].' '.$value['Hours'].':00:00';
         $date =  $this->api_model->display_to_GMT($convertdate,1,$timezone1);
         $calls[$key]['date'] = $date;
         $keyhrsarr[date('H',strtotime($date))]['keydate'] = date('H',strtotime($date));
         $keyhrsarr[date('H',strtotime($date))]['usage'] = $value['usage'];
         $calls[$key]['usage'] = $value['usage'];
         $calls[$key]['hrs'] = date('H',strtotime($date));
         $hrsarr[$key] = date('H',strtotime($date));
       }

       $arr = array();
       $iTimestamp = strtotime($filterhrs);
       $j = 0;
       $newdatepre='';
       for ($i = 0; $i <= 23; $i++) {
           $hrs = date('Y-m-d H:i:s', $iTimestamp);  
           $hrs = $this->api_model->display_to_GMT($hrs,1,$timezone1);
           $hrs = date('H', strtotime($hrs));  
           if(in_array($hrs,$hrsarr)){
             $arr[] = (int)@$keyhrsarr[$hrs]['usage'];               
          }else{
             $arr[] = 0;   
           }
           $j++;
           $iTimestamp += 3600;
       }
      $arr1['data'] = $arr;
      $this->output
             ->set_content_type('application/json')
             ->set_output(json_encode($arr1['data']));
 }

 
 public function getChartNumberOfCalls($company_uuid,$currdate){
     if(date('Y-m-d')==date('Y-m-d',strtotime($currdate))){
         $start_date = date('Y-m-d 00:00:00');
         $end_date = date('Y-m-d H:i:s');           
     }else{
         $start_date = date('Y-m-d H:i:s', strtotime('-1 day'));
         $end_date = date('Y-m-d H:i:s');
     }

     $sql =$this->db->query("SELECT HOUR(start_stamp) AS Hours,day(start_stamp) AS day,month(start_stamp) AS month,year(start_stamp) AS year,COUNT(*) AS `usage` FROM calls WHERE (start_stamp BETWEEN '".$start_date."' AND '".$end_date."') and company_uuid='".$company_uuid."' GROUP BY HOUR(start_stamp), day( start_stamp ) ORDER BY start_stamp desc");

     return $sql->result_array();
   }



   
   function display_to_GMT($convertdate,$offset,$timezone_id){
         $this->db->select('gmtoffset');
         $this->db->from('timezone');
         $this->db->where('id',$timezone_id);
         $query = $this->db->get();
         $timezone_offset = $query->result();

         $USER_GMT = $timezone_offset['0']->gmtoffset;
         // echo $USER_GMT;exit;
         // $USER_GMT = '19800'; // 5:30 Indian Timezone
         $SERVER_GMT='0';
         $date_time_array = getdate(strtotime($convertdate));
         $hours = $date_time_array['hours'];
         $minutes = $date_time_array['minutes'];
         $seconds = $date_time_array['seconds'];
         $month = $date_time_array['mon'];
         $day = $date_time_array['mday'];
         $year = $date_time_array['year'];
         $timestamp = mktime($hours, $minutes, $seconds, $month, $day, $year);
         $timestamp = $timestamp+($USER_GMT-$SERVER_GMT);
         // echo $convertdate.'===='.$timestamp;exit;
         // $date = date("Y-m-d H:i:s", $timestamp);
         if ($offset == 1) {
           $date = date( "Y-m-d H:i:s", $timestamp );
         } else {
           $date = date( "Y-m-d", $timestamp );
         }        
         return $date;
       }

      
       function convert_to_GMT($currDate, $fulldate = 1, $timezone_id = '') {
         $SERVER_GMT = '0';
         $this->db->select('gmtoffset');
         $this->db->from('timezone');
         $this->db->where('id',$timezone_id);
         $query = $this->db->get();
         $timezone_offset = $query->result();

         $USER_GMT = $timezone_offset ['0']->gmtoffset;

         $date_time_array = getdate ( strtotime ( $currDate ) );
         $hours = $date_time_array ['hours'];
         $minutes = $date_time_array ['minutes'];
         $seconds = $date_time_array ['seconds'];
         $month = $date_time_array ['mon'];
         $day = $date_time_array ['mday'];
         $year = $date_time_array ['year'];
         $timestamp1 = mktime ( $hours, $minutes, $seconds, $month, $day, $year );
         // echo '===='.$timestamp1.'===ok';exit;
         $timestamp = $timestamp1 - ($SERVER_GMT + $USER_GMT);

         if ($fulldate == 1) {
           $date = date ( "Y-m-d H:i:s", $timestamp );
         } else {
           $date = date ( "Y-m-d", $timestamp );
         }
         return $date;
       }