PHP | DateTime modify() Function

The DateTime::modify() function is an inbuilt function in PHP which is used to modify or can alter the timestamp of a DateTime object.

Syntax:

• Object oriented style:

  DateTime DateTime::modify( string $modify )

• Procedural style:

  DateTime date_modify( DateTime $object, string $modify )

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

• $object: It specifies the DateTime object returned by date_create() function. This object is modified by DateTime::modify() function.
• $modify: It specifies the date/time string. It is incremented or decremented to modify the DateTime object.

Return Value: This function returns the modified DateTime object on success or False on failure.

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

Program 1 :

<?php
// PHP program to illustrate
// DateTime::modify() function

// Creating a DateTime object
$datetime = new DateTime('2019-09-30');

// Calling of date DateTime::modify() function
// with the increment of 5 days as parameters
$datetime->modify('+5 day');

// Getting the modified date in "y-m-d" format
echo $datetime->format('Y-m-d');

?>

Output:

2019-10-05

Program 2:

<?php
// PHP program to illustrate the
// DateTime::modify() function

// Creating a DateTime object
$datetime = new DateTime('2019-09-30');

// Calling of date DateTime::modify() function
// with the increment of 5 months as parameters
$datetime->modify('+5 month');

// Getting the modified date in "y-m-d" format
echo $datetime->format('Y-m-d');

?>

Output:

2020-03-01

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