date_diff() in PHP

• Purpose:
  date_diff() calculates the difference between two DateTime objects.

• Returns:
  A DateInterval object that contains years, months, days, hours, minutes, seconds, etc., showing the difference.

Basic Syntax:

date_diff(DateTime $datetime1, DateTime $datetime2, bool $absolute = false): DateInterval

• $datetime1, $datetime2 → Two dates you want to compare.
• $absolute → (optional) If true, always returns positive difference.

Simple Example 1: Difference in Days

<?php
$date1 = new DateTime("2025-04-01");
$date2 = new DateTime("2025-04-27");

$diff = date_diff($date1, $date2);
echo $diff->days . " days";  // Output: 26 days
?>

• ->days gives total number of days difference (absolute, without sign).

Example 2: Showing Years, Months, and Days

<?php
$date1 = new DateTime("2022-01-01");
$date2 = new DateTime("2025-04-27");

$diff = date_diff($date1, $date2);
echo $diff->y . " years, ";
echo $diff->m . " months, ";
echo $diff->d . " days";
// Output: 3 years, 3 months, 26 days
?>

• ->y → years, ->m → months, ->d → days

Example 3: Formatting the Difference

You can use format() to customize how you show the difference.

<?php
$date1 = new DateTime("2025-04-01");
$date2 = new DateTime("2025-04-27");

$diff = date_diff($date1, $date2);
echo $diff->format("%R%a days"); // Output: +26 days
?>

• %R → shows the sign (+ or -)
• %a → total days between dates

Example 4: Negative Difference

<?php
$date1 = new DateTime("2025-05-01");
$date2 = new DateTime("2025-04-27");

$diff = date_diff($date1, $date2);
echo $diff->format("%R%a days"); // Output: -4 days
?>

If the second date is earlier, you’ll get a negative difference.

Quick List of format() options: