PHP | DateTime sub() Function

The DateTime::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 DateTime object.

Syntax:

• Object oriented style:

  DateTime DateTime::sub( DateInterval interval )

• Procedural style:

  DateTime date_sub( DateTime $object, DateInterval $interval )

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

• $object: This parameter holds the DateTime object created by date_create() function.
• $interval: This parameter holds the DateInterval object.

Return Values: This function returns the DateTime object after subtraction is done on success or False on failure.

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

Program 1: This program uses DateTime::sub() function to subtract 2 days from given date object.

<?php

// PHP program to illustrate DateTime::sub()
// function

// Creating a new DateTime() object
$datetime = new DateTime('2019-10-03');

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

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

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

Output:

2019-10-01

Program 2: This program uses DateTime::sub() function to subtract the given interval from date object.

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

// Creating a new DateTime() object
$datetime = new DateTime('2019-10-03');

// Initialising an interval
$interval = 'P2Y5M2DT0H30M40S';

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

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

?>

Output:

2017-04-30 23:29:20

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