PHP | DateTime diff() Function

The DateTime::diff() function is an inbuilt function in PHP which is used to return the difference between two given DateTime objects.

Syntax:

• Object oriented style:

  DateInterval DateTime::diff( DateTimeInterface $datetime2,
                                    bool $absolute = FALSE )

  or

  DateInterval DateTimeImmutable::diff( DateTimeInterface $datetime2,
                                    bool $absolute = FALSE )

  or

  DateInterval DateTimeInterface::diff( DateTimeInterface $datetime2,
                                    bool $absolute = FALSE )

• Procedural style:

  DateInterval date_diff( DateTimeInterface $datetime1,
                    DateTimeInterface $datetime2, bool $absolute = FALSE )

Parameters: This function uses two parameters as mentioned above and described below:

• $datetime: This parameter holds the date to compare with first date.
• $absolute: This parameter forced the interval to be positive.

Return Value: This function return the difference between two given DateTime objects.

Below programs illustrate the DateTime::diff() function in PHP:

Program 1:

<?php

// Initialising the two datetime objects
$datetime1 = new DateTime('2019-9-10');
$datetime2 = new DateTime('2019-9-15');

// Calling the diff() function on above
// two DateTime objects
$difference = $datetime1->diff($datetime2);

// Getting the difference between two
// given DateTime objects
echo $difference->format('%R%a days');
?>

Output:

+5 days

Program 2:

<?php

// Initialising the two datetime objects
$datetime1 = new DateTime('2019-8-10');
$datetime2 = new DateTime('2019-9-10');

// Calling the diff() function on above
// two DateTime objects
$difference = $datetime1->diff($datetime2);

// Getting the difference between two
// given DateTime objects
echo $difference->format('%R%a days');
?>

Output:

+31 days

Reference: https://www.php.net/manual/en/datetime.diff.php