PHP | DateTimeImmutable add() Function

The DateTimeImmutable::add() function is an inbuilt function in PHP which is used to add a number of days, months, years, hours, minutes and seconds to a created DateTimeImmutable object. Syntax:

DateTimeImmutable DateTimeImmutable::add( DateInterval $interval )

Parameters: This function accepts a single parameter $interval which holds the number of days or months or years or hours or minutes or seconds which are going to be added to the given DateTimeImmutable object. Return Values: This function returns the final DateTimeImmutable object after addition is done. Below programs illustrate the DateTimeImmutable::add() function in PHP: Program 1: This program uses DateTimeImmutable::add() function to add 2 days to the DateTimeImmutable object. php

<?php
// PHP program to illustrate DateTimeImmutable::add()
// function
  
// Creating a new DateTimeImmutable::add() object
$datetime = new DateTimeImmutable("2019-10-03T10:00:00");

// Initializing a date interval of 2 days
$interval = 'P2D';

// Calling the add() function
$datetime = $datetime->add(new DateInterval($interval));

// Getting a new date time in the
// format of 'Y-m-d H:i:s'
echo $datetime->format('Y-m-d H:i:s');
?>

Program 2: This program uses DateTimeImmutable::add() function to add 'P2Y5M2DT0H30M40S' DateInterval to the DateTimeImmutable object. php

<?php
// PHP program to illustrate DateTimeImmutable::add()
// function
  
// Creating a new DateTimeImmutable::add() object
$datetime = new DateTimeImmutable("2019-10-03T10:00:00");

// Initializing a DateInterval object
$interval = 'P2Y5M2DT0H30M40S';

// Calling the add() function
$datetime = $datetime->add(new DateInterval($interval));

// Getting a new date time in the
// format of 'Y-m-d H:i:s'
echo $datetime->format('Y-m-d H:i:s');
?>

Reference: https://www.php.net/manual/en/datetimeimmutable.add.php