The DateInterval Class

The DateInterval class allows you to work with time intervals in PHP. It is used to store the difference between two dates or to specify an interval in date manipulation methods. The interval is created in a special format.

Syntax

DateInterval::__construct(string $duration)

Interval Format

The format consists of the letter P (period) and elements:

P{y}Y{m}M{d}DT{h}H{m}M{s}S{w}W

In this format: Y - years, M - months, D - days, T - time separator, H - hours, M - minutes, S - seconds, W - weeks.

You need to write the corresponding value before these letters. For example, 3Y will mean three years, and 5Y2M will denote 5 years and 2 months.

After creation, the DateInterval object will contain the following properties:

<?php
	$interval->y  // years
	$interval->m  // months
	$interval->d  // days
	$interval->h  // hours
	$interval->i  // minutes
	$interval->s  // seconds
	$interval->f  // microseconds
	$interval->invert // 1 if the interval is negative
	$interval->days // number of days (if created via diff())
?>

Let's look at the interval's operation with examples:

Example

Let's create an interval of 1 hour, 45 minutes and 30 seconds:

<?php
	$interval = new DateInterval('PT1H45M30S');
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 0
	'm' => 0
	'd' => 0
	'h' => 1
	'i' => 45
	's' => 30
)

Example

Let's create an interval of 3 weeks and 2 days:

<?php
	$interval = new DateInterval('P3W2D');
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 0
	'm' => 0
	'd' => 23
	'h' => 0
	'i' => 0
	's' => 0
)

Example

Let's create an interval of 5 months, 10 days and 6 hours:

<?php
	$interval = new DateInterval('P5M10DT6H');
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 0
	'm' => 5
	'd' => 10
	'h' => 6
	'i' => 0
	's' => 0
)

Example

Let's create an interval of 2 years and 15 minutes:

<?php
	$interval = new DateInterval('P2YT15M');
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 2
	'm' => 0
	'd' => 0
	'h' => 0
	'i' => 15
	's' => 0
)

Example

Let's create an interval of 1 day, 12 hours and 30 seconds:

<?php
	$interval = new DateInterval('P1DT12H30S');
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 0
	'm' => 0
	'd' => 1
	'h' => 12
	'i' => 0
	's' => 30
)

Example

Let's create a negative interval of 1 year and 3 months (interval backwards):

<?php
	$interval = new DateInterval('P1Y3M');
	$interval->invert = 1;
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 1
	'm' => 3
	'd' => 0
	'h' => 0
	'i' => 0
	's' => 0
	'invert' => 1
)

Example

Let's create a negative interval of 2 hours, 30 minutes (interval backwards):

<?php
	$interval = new DateInterval('PT2H30M');
	$interval->invert = 1;
	var_dump($interval);
?>

Code execution result:

DateInterval Object
(
	'y' => 0
	'm' => 0
	'd' => 0
	'h' => 2
	'i' => 30
	's' => 0
	'invert' => 1
)

Example

Let's add an interval to the current date:

<?php
	$date = new DateTime('2023-01-01');
	$interval = new DateInterval('P10D');
	$date->add($interval);
	echo $date->format('Y-m-d');
?>

Code execution result:

'2023-01-11'

Example

Let's calculate the difference between two dates:

<?php
	$date1 = new DateTime('2023-01-01');
	$date2 = new DateTime('2023-02-15');
	$interval = $date1->diff($date2);
	echo $interval->format('%m months %d days');
?>

Code execution result:

'1 months 14 days'

The DateInterval Class

Syntax

Interval Format

Example

Example

Example

Example

Example

Example

Example

Example

Example

See Also