The DateInterval class

(PHP 5 >= 5.3.0, PHP 7)

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 DateTime's constructor supports.

Class synopsis

DateInterval {

/* Properties */

public integer $y ;

public integer $m ;

public integer $d ;

public integer $h ;

public integer $i ;

public integer $s ;

public integer $invert ;

public mixed $days ;

/* Methods */

public __construct ( string $interval_spec )

public static DateInterval createFromDateString ( string $time )

public string format ( string $format )

}

Properties

y

Number of years.

m

Number of months.

d

Number of days.

h

Number of hours.

i

Number of minutes.

s

Number of seconds.

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 DateTime::diff(), then this is the total number of days between the start and end dates. Otherwise, days will be FALSE.

Before PHP 5.4.20/5.5.4 instead of FALSE you will receive -99999 upon accessing the property.

DateInterval::__construct — Creates a new DateInterval object
DateInterval::createFromDateString — Sets up a DateInterval from the relative parts of the string
DateInterval::format — Formats the interval

User Contributed Notes

p dot scheit at ps-webforge dot com

5 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 ...

0bccbf3a at opayq dot com

2 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

computrius

2 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

theDustin

2 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

?>

Joan

2 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.

artur at qrupa dot com

3 years ago


When using DateInterval('P3M') on 30th of November you get March instead of Ferbuary.

Miller

2 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....
?>

cmygind@tsccorp dot com

1 year 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/>';
?>

till at php dot net

2 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");
 }
?>

till at php dot net

2 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");
 }
?>

Michael

1 year ago


To increase a time, use the add method.  For example:

$thirty_minutes_from_now = new DateTime();
$thirty_minutes_from_now->sub(new DateInterval('PT30M'));

To decrease a time, use the diff method.  For example:

$thirty_minutes_ago = new DateTime();
$thirty_minutes_ago->sub(new DateInterval('PT30M'));

The DateInterval class

Introduction

Class synopsis

Properties

Table of Contents

User Contributed Notes