<?php
$db_host = 'localhost'; // Server Name
$db_user = 'root'; // Username
$db_pass = ''; // Password
$db_name = 'login'; // Database Name

$conn = mysqli_connect($db_host, $db_user, $db_pass, $db_name);
if (!$conn) {
die ('Failed to connect to MySQL: ' . mysqli_connect_error());
}

$counter=0;
$sql = "SELECT `OrderID`,`CIDateTime`,`CODateTime` from overall";

$query = mysqli_query($conn, $sql);

if (!$query) {
die ('SQL Error: ' . mysqli_error($conn));
}


    while ($row = mysqli_fetch_array($query))
    {

            $startTS = strtotime($row['CIDateTime']);
            $endTS   = strtotime($row['CODateTime']);

            $start_TS = date('H:i',strtotime($row['CIDateTime']));
            $end_TS   = date('H:i',strtotime($row['CODateTime']));


        $start='08:30';
       $start = strtotime($start);
       $end='17:00';
       $end = strtotime($end);

if($start_TS >= '08:30')
{
if(date('Y-m-d', $startTS) == date('Y-m-d', $endTS))
{
   if($start_TS >= '08:30' && $end_TS == '00:00')
   {
        $work_seconds = round((time() - $startTS)/60,0);
        $hour = floor($work_seconds / 60).':'.($work_seconds -
floor($work_seconds / 60) * 60);
        $hours=floor($hour);
   }
   elseif($start_TS >= '08:30' && $end_TS <= '13:00')
   {
        $work_seconds = round(($endTS - $startTS)/60,0);
        $hour = floor($work_seconds / 60).':'.($work_seconds -
floor($work_seconds / 60) * 60);
        $hours=floor($hour);

   }
   elseif($start_TS >= '13:30' && $end_TS <= '17:00')
   {
        $work_seconds = round(($endTS - $startTS)/60,0);
        $hour = floor($work_seconds / 60).':'.($work_seconds -
floor($work_seconds / 60) * 60);
        $hours=floor($hour);

   }
   elseif($start_TS >= '08:30' && $end_TS <= '17:00')
   {
        $work_seconds = round(($endTS - $startTS - 1800)/60,0);
        $hours = floor($work_seconds / 60).':'.($work_seconds -
floor($work_seconds / 60) * 60);
        $hours=floor($hour);
   }
}
if(date('Y-m-d', $startTS) != date('Y-m-d', $endTS))

{
if($start_TS >= '08:30' && $end_TS <= '17:00')
{
    $start_TS = strtotime($start_TS);
       $end_TS = strtotime($end_TS);
        $a=($end-$start_TS)/60;
        $b=($end_TS-$start-1800)/60;
        $minutes=$a+$b;
       $hours = floor($minutes / 60).':'.($minutes -   floor($minutes /
60) * 60);

}
elseif($start_TS >= '13:30' && $end_TS >= '13:30')
{
        $start_TS = strtotime($start_TS);
       $end_TS = strtotime($end_TS);
        $a=($end-$start_TS)/60;

       $b=($end_TS-$start-1800)/60;

       $minutes=$a+$b;
       $hours = floor($minutes / 60).':'.($minutes -   floor($minutes /
60) * 60);
}

elseif($start_TS >= '13:30' && $end_TS <= '13:00')
   {

        $start_TS = strtotime($start_TS);
       $end_TS = strtotime($end_TS);

       $a=($end-$start_TS)/60;

       $b=($end_TS-$start)/60;

       $minutes=$a+$b;
       $hours = floor($minutes / 60).':'.($minutes -   floor($minutes /
60) * 60);

   }
elseif($start_TS >= '08:30' && $end_TS <= '13:00')
   {
       $start_TS = strtotime($start_TS);
       $end_TS = strtotime($end_TS);
        $a=($end-$start_TS-1800)/60;

       $b=($end_TS-$start_TS)/60;

       $minutes=$a+$b;
       $hours = floor($minutes / 60).':'.($minutes -   floor($minutes /
60) * 60);
   }

}
}

        echo '<tr>

                <td>'.++$counter.'</td>
                <td>'.$row['OrderID'].'</td>
                <td>'.$row['CIDateTime'].'</td>
                <td>'.$row['CODateTime'].'</td>
                <td>'.$hours.' Hrs</td>

            </tr>';

    }

?>