PHP add time duration in while loop - php

Question

I am calculating time duration in while loop by difference of login time and logout time. I want to add all the time duration in a variable and print it out.
The code for this I am using is -
$totaltimespent = new DateTime;
$totaltimespent->setTime(0, 0);
$timespent= (strtotime($totaltimespent->format("H:i:s")));
while ($row = mysqli_fetch_array($result)) {
echo $row['timeoflogin'];
echo $row['logouttime'];
$startTime = new DateTime($row['timeoflogin']);
$endTime = new DateTime($row['logouttime']);
$duration = $startTime->diff($endTime);
echo $duration->format("%H:%I:%S");
$converttime= (strtotime($duration->format("%H:%I:%S")));
$timespent = date("H:i:s",$converttime+$timespent);
}
echo $timespent;
The timeoflogin and logouttime are in format - 05:03:53pm. The $duration is giving right result. I want to add this all duration in varaible and print after while loop. Please help me out.

Answer 1

You can simply add the difference you already calculated inside the loop to another DateTime object and get the final difference between them.
$totalStart = new DateTime('today'); // this will create it with time 00:00:00
$totalEnd = new DateTime('today'); // we will use this to add the intervals from the loop
while ($row = mysqli_fetch_array($result)) {
...
$startTime = new DateTime($row['timeoflogin']);
$endTime = new DateTime($row['logouttime']);
$duration = $startTime->diff($endTime);
$totalEnd->add($duration);
...
}
$totalTimeSpent = $totalStart->diff($totalEnd);
Now all you need to do is format it the way you want to.