The DateInterval class

(PHP 5 >= 5.3.0, PHP 7, PHP 8)

Introduction

Represents a date interval.

A date interval stores either a fixed amount of time (in years, months, days, hours etc) or a relative time string in the format that DateTimeImmutable's and DateTime's constructors support.

More specifically, the information in an object of the DateInterval class is an instruction to get from one date/time to another date/time. This process is not always reversible.

A common way to create a DateInterval object is by calculating the difference between two date/time objects through DateTimeInterface::diff().

Since there is no well defined way to compare date intervals, DateInterval instances are incomparable.

Class synopsis

class DateInterval {
/* Properties */
public int $y;
public int $m;
public int $d;
public int $h;
public int $i;
public int $s;
public float $f;
public int $invert;
public mixed $days;
/* Methods */
public __construct(string $duration)
public static createFromDateString(string $datetime): DateInterval|false
public format(string $format): string
}

Properties

Warning

The available properties listed below depend on PHP version, and should be considered as readonly.

y

Number of years.

m

Number of months.

d

Number of days.

h

Number of hours.

i

Number of minutes.

s

Number of seconds.

f

Number of microseconds, as a fraction of a second.

invert

Is 1 if the interval represents a negative time period and 0 otherwise. See DateInterval::format().

days

If the DateInterval object was created by DateTimeImmutable::diff() or DateTime::diff(), then this is the total number of full days between the start and end dates. Otherwise, days will be false.

from_string

If the DateInterval object was created by DateInterval::createFromDateString(), then this property's value will be true, and the date_string property will be populated. Otherwise, the value will be false, and the y to f, invert, and days properties will be populated.

date_string

The string used as argument to DateInterval::createFromDateString().

Changelog

Version Description
8.2.0 The from_string and date_string properties were added for DateInterval instances that were created using the DateInterval::createFromDateString() method.
8.2.0 Only the y to f, invert, and days will be visible.
7.4.0 DateInterval instances are incomparable now; previously, all DateInterval instances were considered equal.
7.1.0 The f property was added.

Table of Contents

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User Contributed Notes 18 notes

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46
trap-phpdocs-06022017 at skvorc dot me
7 years ago
IRT note below: from PHP 7.0+, split seconds get returned, too, and will be under the `f` property.
up
25
ruth45007
4 years ago
Just tried the code submitted earlier on php 7.2.16:

<?php
$d1
=new DateTime("2012-07-08 11:14:15.638276");
$d2=new DateTime("2012-07-08 11:14:15.889342");
$diff=$d2->diff($d1);
print_r( $diff ) ;
?>

and it now DOES return microsecond differences, in the key 'f':

<?php
DateInterval Object
(
    [
y] => 0
   
[m] => 0
   
[d] => 0
   
[h] => 0
   
[i] => 0
   
[s] => 0
   
[f] => 0.251066
   
[weekday] => 0
   
[weekday_behavior] => 0
   
[first_last_day_of] => 0
   
[invert] => 1
   
[days] => 0
   
[special_type] => 0
   
[special_amount] => 0
   
[have_weekday_relative] => 0
   
[have_special_relative] => 0
)
?>
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69
php at keith tyler dot com
11 years ago
DateInterval does not support split seconds (microseconds or milliseconds etc.) when doing a diff between two DateTime objects that contain microseconds.

So you cannot do the following, for example:

<?php
$d1
=new DateTime("2012-07-08 11:14:15.638276");
$d2=new DateTime("2012-07-08 11:14:15.889342");
$diff=$d2->diff($d1);
print_r( $diff ) ;

/* returns:

DateInterval Object
(
    [y] => 0
    [m] => 0
    [d] => 0
    [h] => 0
    [i] => 0
    [s] => 0
    [invert] => 0
    [days] => 0
)

*/
?>

You get back 0 when you actually want to get 0.251066 seconds.
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42
p dot scheit at ps-webforge dot com
13 years ago
If you want to convert a Timespan given in Seconds into an DateInterval Object you could dot the following:

<?php

$dv
= new DateInterval('PT'.$timespan.'S');
?>

but wenn you look at the object, only the $dv->s property is set.

As stated in the documentation to DateInterval::format

The DateInterval::format() method does not recalculate carry over points in time strings nor in date segments. This is expected because it is not possible to overflow values like "32 days" which could be interpreted as anything from "1 month and 4 days" to "1 month and 1 day".

If you still want to calculate the seconds into hours / days / years, etc do the following:

<?php

$d1
= new DateTime();
$d2 = new DateTime();
$d2->add(new DateInterval('PT'.$timespan.'S'));
     
$iv = $d2->diff($d1);

?>

$iv is an DateInterval set with days, years, hours, seconds, etc ...
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6
nateb at gurutechnologies dot net
3 years ago
Many people have commented on doing a reverse interval on a date time.  I personally find a backwards year to be a little strange to think about and instead opt to work with just intervals.  This is the easiest I have found.

<?php
$one_year
= new DateInterval('P1Y');
$one_year_ago = new DateTime();
$one_year_ago->sub($one_year);
?>

Instead of:

<?php
$one_year_ago
= new DateInterval( "P1Y" );
$one_year_ago->invert = 1;
$one_year_ago = new DateTime();
$one_year_ago->add($one_year);
?>
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3
Aurelien Marchand
4 years ago
Please note that the hour field can be negative, especially in the context of switching to/from Daylight savings.

Example:
<?php

$tz
= new DateTimeZone("America/New_York");
$date_1 = new DateTime("2019-10-30 15:00:00",$tz);
$date_2 = new DateTime("2019-11-21 14:30:20",$tz);

echo
$date_2->diff($date_1)->format("%a:%h:%i:%s");

// returns 21:-1:30:20
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7
0bccbf3a at opayq dot com
9 years ago
invert flag is unreliable.
If you've created interval with \DateInterval::createFromDateString with value like '1 day ago' than actually days counter will be negative, and invert flag will be 0. Also, setting invert to 1 with negative units is not working.
Reliable solution to check if interval is negative is to actually apply it and compare:
<?php
   
private function isNegative(\DateInterval $interval)
    {
       
$now = new \DateTimeImmutable();
       
$newTime = $now->add($interval);
        return
$newTime < $now;
    }
?>
Also, if you want to compare some units of two intervals you should take abs() of them. Or make whole interval absolute:
<?php
   
private function absInterval(\DateInterval $interval)
    {
       
$now = new \DateTimeImmutable();
       
$new = $now->add($interval);
       
$newInt = $now->diff($new);
        if (
1 === $newInt->invert) {
           
$newInt->invert = 0;
        }
        return
$newInt;
    }
?>
P.S.: tested on 5.5.12-dev and 5.5.9
up
4
Miller
10 years ago
This DateInterval extension allows you to write a formatted timestamp but omit the "zero values" and handle things like listing, plurals, etc.
Example input: '%y year(s)', '%m month(s)', '%d day(s)', '%h hour(s)', '%i minute(s)', '%s second(s)'
Example output: 1 year, 2 months, 16 days, 1 minute, and 15 seconds
Example input: '%y año(s)', '%m mes(es)', '%d día(s)', '%h hora(s)', '%i minuto(s)', '%s segundo(s)'
Example output: 1 año, 2 meses, 16 días, 1 minuto, y 15 segundos

<meta charset="UTF-8">
<?php
error_reporting
(E_ALL);

class
MyDateInterval extends DateInterval {
    public
       
$pluralCheck = '()',
           
// Must be exactly 2 characters long
            // The first character is the opening brace, the second the closing brace
            // Text between these braces will be used if > 1, or replaced with $this->singularReplacement if = 1
       
$singularReplacement = '',
           
// Replaces $this->pluralCheck if = 1
            // hour(s) -> hour
       
$separator = ', ',
           
// Delimiter between units
            // 3 hours, 2 minutes
       
$finalSeparator = ', and ',
           
// Delimeter between next-to-last unit and last unit
            // 3 hours, 2 minutes, and 1 second
       
$finalSeparator2 = ' and ';
           
// Delimeter between units if there are only 2 units
            // 3 hours and 2 minutes

   
public static function createFromDateInterval (DateInterval $interval) {
       
$obj = new self('PT0S');
        foreach (
$interval as $property => $value) {
           
$obj->$property = $value;
        }
        return
$obj;
    }

    public function
formatWithoutZeroes () {
       
// Each argument may have only one % parameter
        // Result does not handle %R or %r -- but you can retrieve that information using $this->format('%R') and using your own logic
       
$parts = array ();
        foreach (
func_get_args() as $arg) {
           
$pre = mb_substr($arg, 0, mb_strpos($arg, '%'));
           
$param = mb_substr($arg, mb_strpos($arg, '%'), 2);
           
$post = mb_substr($arg, mb_strpos($arg, $param)+mb_strlen($param));
           
$num = intval(parent::format($param));

           
$open = preg_quote($this->pluralCheck[0], '/');
           
$close = preg_quote($this->pluralCheck[1], '/');
           
$pattern = "/$open(.*)$close/";
            list (
$pre, $post) = preg_replace($pattern, $num == 1 ? $this->singularReplacement : '$1', array ($pre, $post));

            if (
$num != 0) {
               
$parts[] = $pre.$num.$post;
            }
        }

       
$output = '';
       
$l = count($parts);
        foreach (
$parts as $i => $part) {
           
$output .= $part.($i < $l-2 ? $this->separator : ($l == 2 ? $this->finalSeparator2 : ($i == $l-2 ? $this->finalSeparator : '')));
        }
        return
$output;
    }
}

date_default_timezone_set('America/Phoenix');

$today = new DateTime('today');
echo
'Today is ', $today->format('F d, Y h:ia'), '.<br>', PHP_EOL;
   
// Today is August 28, 2013 12:00am.<br>
$expiration = new DateTime('today +1 year +2 months +16 days +1 minute +15 seconds');
echo
'Expires ', $expiration->format('F d, Y h:ia'), '.<br>', PHP_EOL;
   
// Expires November 13, 2014 12:01am.<br>

$interval = MyDateInterval::createFromDateInterval($today->diff($expiration));

echo
'That is ', $interval->formatWithoutZeroes('%y year(s)', '%m month(s)', '%d day(s)', '%h hour(s)', '%i minute(s)', '%s second(s)'), ' from now.<br>', PHP_EOL;
   
// That is 1 year, 2 months, 16 days, 1 minute, and 15 seconds from now.

$interval->finalSeparator = ', y ';
$interval->finalSeparator2 = ' y ';
echo
'Que es de ', $interval->formatWithoutZeroes('%y año(s)', '%m mes(es)', '%d día(s)', '%h hora(s)', '%i minuto(s)', '%s segundo(s)'), ' a partir de ahora.';
   
// Que es de 1 año, 2 meses, 16 días, 1 minuto, y 15 segundos a partir de ahora.
    // Is that correct? Spanish isn't my strength....
?>
up
4
theDustin
10 years ago
If you want to format a \DateInterval to something like you input (new \DateInterval("P3W2D")) you can use one of this:

<?php

class MyDateInterval extends \DateInterval
{

   
/**
     * formating string like ISO 8601 (PnYnMnDTnHnMnS)
     */
   
const INTERVAL_ISO8601 = 'P%yY%mM%dDT%hH%iM%sS';

   
/**
     * formating the interval like ISO 8601 (PnYnMnDTnHnMnS)
     *
     * @return string
     */
   
function __toString()
    {
       
$sReturn = 'P';

        if(
$this->y){
           
$sReturn .= $this->y . 'Y';
        }

        if(
$this->m){
           
$sReturn .= $this->m . 'M';
        }

        if(
$this->d){
           
$sReturn .= $this->d . 'D';
        }

        if(
$this->h || $this->i || $this->s){
           
$sReturn .= 'T';

            if(
$this->h){
               
$sReturn .= $this->h . 'H';
            }

            if(
$this->i){
               
$sReturn .= $this->i . 'M';
            }

            if(
$this->s){
               
$sReturn .= $this->s . 'S';
            }
        }

        return
$sReturn;
    }
}

?>

example use:

<?php

$oDateIntervalValue
= new MyDateInterval('P3M');

$sFormatResult = $oDateIntervalValue->format(MyDateInterval::INTERVAL_ICALENDAR); // "P0Y3M0DT0H0M0S"
$sToStringResult = (string) $oDateIntervalValue; // "P3M"

var_dump(new MyDateInterval($sFormatResult)); // object like $oDateIntervalValue
var_dump(new MyDateInterval($sToStringResult)); // object like $oDateIntervalValue

?>
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0
KEINOS
3 years ago
Note that you CAN NOT get the exact time in seconds from a \DateInterval object.

The reason is simple. While adding the properties up, you can not determine the days of the month.

<?php
function getTTL(\DateInterval $ttl): int
{
   
$secs = (isset($ttl->f) ? ($ttl->f): 0)
        + (
$ttl->s)
        + (
$ttl->i * 60)
        + (
$ttl->h * 60 * 60)
        + (
$ttl->d * 60 * 60 * 24)
        + (
$ttl->m * 60 * 60 * 24 * 30) //Feb. is 28 days, 29 in an intercalary year
       
+ ($ttl->y * 60 * 60 * 24 * 365);

    return
intval(round($secs));
}
?>

So, keep in mind that \DateInterval is something to add-on to time.

<?php
function getTTL(\DateInterval $ttl): int
{
   
// Find seconds from it's current state of time
   
$secs = \DateTime::createFromFormat('U', '0')->add($ttl)->format('U');

    return
intval(abs($secs));
}
?>
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0
tothsanka at gmail dot com
4 years ago
Be careful!

2020-01-04 10:00:00
2020-01-05 10:00:00

->s will return 0, because the second difference is 0.
up
1
artur at qrupa dot com
11 years ago
When using DateInterval('P3M') on 30th of November you get March instead of Ferbuary.
up
-1
cmygind@tsccorp dot com
9 years ago
You can create a series of dates starting with the first day of the week for each week, if you wish to populate list box on your web page with this date math. Use the absolute abs( ) function to convert negative numbers generated from dates in the past.
<?php
            $TwoWeeksAgo
= new DateTime(date("Ymd"));
           
$TwoWeeksAgo->sub(new DateInterval('P'.abs ( (7-date("N")-14)).'D'));
           
$LastWeek = new DateTime(date("Ymd"));
           
$LastWeek->sub(new DateInterval('P'.abs ( (7-date("N")-7)).'D'));
           
$ThisWeek = new DateTime(date("Ymd"));
           
$ThisWeek->add(new DateInterval('P'.abs ( (7-date("N"))).'D'));

            echo
'Start of This week is '.$ThisWeek->format('l m/d/Y').'<br/>';
            echo
'Start of Last week is '.$LastWeek->format('l m/d/Y').'<br/>';
            echo
'Start of 2 weeks ago is '.$TwosWeekAgo->format('l m/d/Y').'<br/>';
?>
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-2
computrius
10 years ago
It appears that they "days" property that is populated by \DateTime::diff does not contain a float for the differences in time.
It is rounded down to the nearest whole day.

    $d1 = new \DateTime("2013-07-31 10:29:00");
    $d2 = new \DateTime("2013-08-02 5:32:12");
    echo $d1->diff($d2)->days;

Output: 1
up
-2
Joan
10 years ago
I had the doubt after reading this page on how to create negative intervals. So far the only solution is to create the interval and negativize it.

<?php
$date1
= new DateTime();
$eightynine_days_ago = new DateInterval( "P89D" );
$eightynine_days_ago->invert = 1; //Make it negative.
$date1->add( $eightynine_days_ago );
?>

and then $date1 is now 89 days in the past.

This information is extracted from another php comment http://www.php.net/manual/en/dateinterval.construct.php#102976 but this page seems to be the first place where people will look for it.
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-1
youssef dot benhssaien at gmail dot com
4 years ago
Note that to get the next day (like : +1 day, +1 week, ...)
<?php $date = date_create('last monday of december last year')->add(\DateInterval::createFromDateString('+1 monday')); ?>
will not return the next monday, but the same monday passed as date_create() parameter.
To get the next monday even pass +2 instead of +1 or next monday :
<?php $date = date_create('last monday of december last year')->add(\DateInterval::createFromDateString('next monday')); ?>
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-1
Anonymous
4 years ago
//create a date
$now = new \DateTime();

//create a specific date
$someDate = \DateTime::createFromFormat("Y-m-d H:i", "2019-12-19 15:27")

//Add one day
$someDate->add(new DateInterval("P1D"));

//convert to string
echo $someDate->format("Y-m-d");   //2019-12-20
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-21
till at php dot net
10 years ago
It should be noted that the following code will not throw an exception or return false, or anything:

<?php
$interval
= new \DateInterval::createFromDateString("this is not a date interval");
?>

Your best way to check if what you created is a "valid" interval, by doing something like the following:

<?php
$interval
= new \DateInterval::createFromDateString("this is not a date interval");
if (
0 == $interval->format('s')) {
     throw new \
LogicException("Wrong interval");
}
?>
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