Calculating the Difference Between Two Time Periods in PHP

PHP is a server-side scripting language extensively used in web development. Whether you're developing an appointment booking system, tracking user sessions, or generating logs, calculating the time difference between two periods is a common task.

PHP makes this process easy with its powerful DateTime and DateInterval classes.

In this sub-article, we’ll write a PHP program that calculates the difference between two specific date-time values using object-oriented time handling.

This article complements our lead C article with an elegant PHP solution.

PHP Program: Calculate the Difference Between Two Time Periods

<?php
// DIFFERENCE BETWEEN TWO TIME PERIODS in PHP using DateTime class

// Step-1 Define two datetime strings
$start = new DateTime("2025-11-05 10:15:00");
$end = new DateTime("2025-11-13 17:40:25");

// Step-2 Calculate the difference
$interval = $start->diff($end);

// Step-3 Extract hours, minutes, and seconds
$totalHours = ($interval->days * 24) + $interval->h;
$minutes = $interval->i;
$seconds = $interval->s;

// Step-4 Display the result
echo "\nTIME DIFFERENCE: {$totalHours} HOURS, {$minutes} MINUTES, {$seconds} SECONDS";

?>

Run

Output

Explanation

• DateTime creates immutable objects to represent the date and time.

• diff() returns a DateInterval object that stores the full difference.

• The total hours are calculated by converting the number of days to hours and adding the remaining hours.

This approach is ideal for server-side applications, billing systems, or any web-based service that involves time tracking or scheduling.

Extra Metric: Total Duration in Minutes

If you need to log durations for reporting or database storage, you can compute the total minutes like this:

$totalMinutes = ($interval->days * 24 * 60) + ($interval->h * 60) + $interval->i;

echo "\nTOTAL DURATION IN MINUTES: {$totalMinutes}";

Output

This kind of metric is especially useful in usage-based pricing models or performance tracking dashboards.