PHP | DateTimeImmutable::sub() Function

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

Syntax:

DateTimeImmutable::sub( interval )

Parameters: This function accepts a parameter interval which is the number of days or months or years or hours or minutes or seconds which are going to be subtracted from the given DateTimeImmutable object.

Return Values: : This function returns the final datetime after subtraction is done.

Below programs illustrate the DateTimeImmutable::sub() function:

Program 1: This program decreases the days by 2.

<?php
// PHP program to illustrate DateTimeImmutable::sub()
// function

// Creating a new DateTimeImmutable() object
$datetimeImmutable = new DateTimeImmutable('2019-10-07');

// Initialising a interval of 2 days
$interval = 'P2D';

// Calling the DateTimeImmutable::sub() function
$a = $datetimeImmutable->sub(new DateInterval($interval));

// Getting a new date time
// format of 'Y-m-d'
echo $a->format('Y-m-d');
?>

Output:

2019-10-05

Program 2: This program decreases the month by 5.

<?php
// PHP program to illustrate DateTimeImmutable::sub()
// function

// Creating a new DateTimeImmutable() object
$datetimeImmutable = new DateTimeImmutable('2019-10-07');

// Initialising a interval of 5 months
$interval = 'P5M';

// Calling the DateTimeImmutable::sub() function
$a = $datetimeImmutable->sub(new DateInterval($interval));

// Getting a new date time
// format of 'Y-m-d'
echo $a->format('Y-m-d');
?>

Output:

2019-05-07

Reference
https://devdocs.io/php/datetimeimmutable.sub