DateTime::add

[edit] Last updated: Fri, 25 May 2012

The DateTime class

(PHP 5 >= 5.2.0)

Introduction

Representation of date and time.

Class synopsis

DateTime {

/* Constants */

const string ATOM = "Y-m-d\TH:i:sP" ;

const string COOKIE = "l, d-M-y H:i:s T" ;

const string ISO8601 = "Y-m-d\TH:i:sO" ;

const string RFC822 = "D, d M y H:i:s O" ;

const string RFC850 = "l, d-M-y H:i:s T" ;

const string RFC1036 = "D, d M y H:i:s O" ;

const string RFC1123 = "D, d M Y H:i:s O" ;

const string RFC2822 = "D, d M Y H:i:s O" ;

const string RFC3339 = "Y-m-d\TH:i:sP" ;

const string RSS = "D, d M Y H:i:s O" ;

const string W3C = "Y-m-d\TH:i:sP" ;

/* Methods */

public __construct ([ string $time = "now" [, DateTimeZone $timezone = NULL ]] )

public DateTime add ( DateInterval $interval )

public static DateTime createFromFormat ( string $format , string $time [, DateTimeZone $timezone ] )

public DateInterval diff ( DateTime $datetime2 [, bool $absolute = false ] )

public string format ( string $format )

public static array getLastErrors ( void )

public int getOffset ( void )

public int getTimestamp ( void )

public DateTimeZone getTimezone ( void )

public DateTime modify ( string $modify )

public static DateTime __set_state ( array $array )

public DateTime setDate ( int $year , int $month , int $day )

public DateTime setISODate ( int $year , int $week [, int $day = 1 ] )

public DateTime setTime ( int $hour , int $minute [, int $second = 0 ] )

public DateTime setTimestamp ( int $unixtimestamp )

public DateTime setTimezone ( DateTimeZone $timezone )

public DateTime sub ( DateInterval $interval )

public DateTime __wakeup ( void )

}

Predefined Constants

DateTime::ATOM
DATE_ATOM: Atom (example: 2005-08-15T15:52:01+00:00)
DateTime::COOKIE
DATE_COOKIE: HTTP Cookies (example: Monday, 15-Aug-05 15:52:01 UTC)
DateTime::ISO8601
DATE_ISO8601: ISO-8601 (example: 2005-08-15T15:52:01+0000)
DateTime::RFC822
DATE_RFC822: RFC 822 (example: Mon, 15 Aug 05 15:52:01 +0000)
DateTime::RFC850
DATE_RFC850: RFC 850 (example: Monday, 15-Aug-05 15:52:01 UTC)
DateTime::RFC1036
DATE_RFC1036: RFC 1036 (example: Mon, 15 Aug 05 15:52:01 +0000)
DateTime::RFC1123
DATE_RFC1123: RFC 1123 (example: Mon, 15 Aug 2005 15:52:01 +0000)
DateTime::RFC2822
DATE_RFC2822: RFC 2822 (Mon, 15 Aug 2005 15:52:01 +0000)
DateTime::RFC3339
DATE_RFC3339: Same as DATE_ATOM (since PHP 5.1.3)
DateTime::RSS
DATE_RSS: RSS (Mon, 15 Aug 2005 15:52:01 +0000)
DateTime::W3C
DATE_W3C: World Wide Web Consortium (example: 2005-08-15T15:52:01+00:00)

Changelog

Version	Description
5.2.2	DateTime object comparison with the comparison operators changed to work as expected. Previously, all DateTime objects were considered equal (using ==).

DateTime::add — Adds an amount of days, months, years, hours, minutes and seconds to a DateTime object
DateTime::__construct — Returns new DateTime object
DateTime::createFromFormat — Returns new DateTime object formatted according to the specified format
DateTime::diff — Returns the difference between two DateTime objects
DateTime::format — Returns date formatted according to given format
DateTime::getLastErrors — Returns the warnings and errors
DateTime::getOffset — Returns the timezone offset
DateTime::getTimestamp — Gets the Unix timestamp
DateTime::getTimezone — Return time zone relative to given DateTime
DateTime::modify — Alters the timestamp
DateTime::__set_state — The __set_state handler
DateTime::setDate — Sets the date
DateTime::setISODate — Sets the ISO date
DateTime::setTime — Sets the time
DateTime::setTimestamp — Sets the date and time based on an Unix timestamp
DateTime::setTimezone — Sets the time zone for the DateTime object
DateTime::sub — Subtracts an amount of days, months, years, hours, minutes and seconds from a DateTime object
DateTime::__wakeup — The __wakeup handler

DateTime::add

Predefined Constants

[edit] Last updated: Fri, 25 May 2012

add a note User Contributed Notes DateTime

marcio dot barbado at bdslabs dot com dot br 22-Mar-2012 06:22


DateTime class does not use locales so here I test and compare its formating with strftime() function's one:



    <?php

      // Under UNIX, command "$ locale -a" should provide you with your server's options.



      $data_do_mysql            = "2011-09-29 23:50:26";



      echo '<strong>' . "\$data_do_mysql" . '</strong>' . ":" . $data_do_mysql . "." . '<br />' .

           '<br />';



      $dataInicial            = new DateTime(trim($data_do_mysql));



      // setlocale() used with strftime().

      $meu_locale            = setlocale(LC_ALL, "pt_BR.utf8");

      $data_inicial            = strftime("%d de %b de %Y", strtotime(trim($data_do_mysql)));



      // Outputs:

      // $data_do_mysql formatada com a classe DateTime:29-Sep-2011.

      echo '<strong>' . "\$data_do_mysql" . '</strong>' . " formatada com a classe DateTime:" . $dataInicial->format('d-M-Y') . "." . '<br />' .

           '<br />';



      // Outputs:

      // $data_do_mysql formatada com a função strftime():29 de Set de 2011.

      echo '<strong>' . "\$data_do_mysql" . '</strong>' . " formatada com a fun&ccedil;&atilde;o strftime():" . $data_inicial . "." . '<br />' .

           '<br />';



      // setlocale() fails :-(

      if (!$meu_locale)

        {

            echo "Prefiro usar DateTime.";

        }



      // Yay setlocale() :-D

      else

        {

            echo "Prefiro usar strftime().";

        }



      exit();

    ?>

nodweber at gmail dot com 19-Jul-2011 02:22


IF You want to create clone of $time, use clone..



<?php

  $now   = new DateTime;

  $clone = $now;        //this doesnot clone so:

  $clone->modify( '-1 day' );

 

  echo $now->format( 'd-m-Y' ), "\n", $clone->format( 'd-m-Y' );

  echo '----', "\n";



  // will print same.. if you want to clone make like this:

  $now   = new DateTime;

  $clone = clone $now;    

  $clone->modify( '-1 day' );

    

  echo $now->format( 'd-m-Y' ), "\n", $clone->format( 'd-m-Y' );

?>



Results:

18-07-2011

18-07-2011

----

19-07-2011

18-07-2011

giorgio dot liscio at email dot it 13-Aug-2010 10:24


please note that using





setTimezone


setTimestamp


setDate


setTime


etc..





will modify the original object, and the return value is $this





$original = new DateTime("now");





$modified = $original->setTimezone(new DateTimezone("europe/rome"));





echo $original === $modified ? "THE OBJECT IS THE SAME" : "OBJECTS ARE DIFFERENT";





so a datetime object is mutable

bf at tbwb dot nl 10-Aug-2010 03:19


If you have timezone information in the time string you construct the DateTime object with, you cannot add an extra timezone in the constructor. It will ignore the timezone information in the time string:



$date = new DateTime("2010-07-05T06:00:00Z", new DateTimeZone("Europe/Amsterdam"));



will create a DateTime object set to "2010-07-05 06:00:00+0200" (+2 being the TZ offset for Europe/Amsterdam)



To get this done, you will need to set the timezone separately:



$date = new DateTime("2010-07-05T06:00:00Z");

$date->setTimeZone(new DateTimeZone("Europe/Amsterdam");



This will create a DateTime object set to "2010-07-05 08:00:00+0200"

ediathome 20-Mar-2010 01:21


If you need DateTime::createFromFormat functionality in versions <5.3.0 releases you might use the following basic class which can also be combined with Tom's class. It should work for most basic formats, however you should improve this function if you need more complex formats.



<?php

class DateClass extends DateTime{



public function getTimestamp(){

    return $this->format ("U");

}



/**

*    This function calculates the number of days between the first and the second date. Arguments must be subclasses of DateTime

**/

static function differenceInDays ($firstDate, $secondDate){

    $firstDateTimeStamp = $firstDate->format("U");

    $secondDateTimeStamp = $secondDate->format("U");

    $rv = round ((($firstDateTimeStamp - $secondDateTimeStamp))/86400);

    return $rv;

}



/**

* This function returns an object of DateClass from $time in format $format. See date() for possible values for $format

**/

static function createFromFormat ($format, $time){

    assert ($format!="");

    if($time==""){ 

        return new DateClass();

    }



    $regexpArray['Y'] = "(?P<Y>19|20\d\d)";        

    $regexpArray['m'] = "(?P<m>0[1-9]|1[012])";

    $regexpArray['d'] = "(?P<d>0[1-9]|[12][0-9]|3[01])";

    $regexpArray['-'] = "[-]";

    $regexpArray['.'] = "[\. /.]";

    $regexpArray[':'] = "[:]";            

    $regexpArray['space'] = "[\s]";

    $regexpArray['H'] = "(?P<H>0[0-9]|1[0-9]|2[0-3])";

    $regexpArray['i'] = "(?P<i>[0-5][0-9])";

    $regexpArray['s'] = "(?P<s>[0-5][0-9])";



    $formatArray = str_split ($format);

    $regex = "";



    // create the regular expression

    foreach($formatArray as $character){

        if ($character==" ") $regex = $regex.$regexpArray['space'];

        elseif (array_key_exists($character, $regexpArray)) $regex = $regex.$regexpArray[$character];

    }

    $regex = "/".$regex."/";



    // get results for regualar expression

    preg_match ($regex, $time, $result);



    // create the init string for the new DateTime

    $initString = $result['Y']."-".$result['m']."-".$result['d'];



// if no value for hours, minutes and seconds was found add 00:00:00

    if (isset($result['H'])) $initString = $initString." ".$result['H'].":".$result['i'].":".$result['s'];

    else {$initString = $initString." 00:00:00";}



    $newDate = new DateClass ($initString);

    return $newDate;

    }    

}



?>

gmblar+php at gmail dot com 24-Jan-2010 08:53


Small but powerful extension to DateTime



<?php



class Blar_DateTime extends DateTime {



    /**

     * Return Date in ISO8601 format

     *

     * @return String

     */

    public function __toString() {

        return $this->format('Y-m-d H:i');

    }



    /**

     * Return difference between $this and $now

     *

     * @param Datetime|String $now

     * @return DateInterval

     */

    public function diff($now = 'NOW') {

        if(!($now instanceOf DateTime)) {

            $now = new DateTime($now);

        }

        return parent::diff($now);

    }



    /**

     * Return Age in Years

     *

     * @param Datetime|String $now

     * @return Integer

     */

    public function getAge($now = 'NOW') {

        return $this->diff($now)->format('%y');

    }



}



?>



Usage:



<?php



$birthday = new Blar_DateTime('1879-03-14');



// Example 1

echo $birthday;

// Result: 1879-03-14 00:00



// Example 2

echo '<p>Albert Einstein would now be ', $birthday->getAge(), ' years old.</p>';

// Result: <p>Albert Einstein would now be 130 years old.</p>



// Example 3

echo '<p>Albert Einstein would now be ', $birthday->diff()->format('%y Years, %m Months, %d Days'), ' old.</p>';

// Result: <p>Albert Einstein would now be 130 Years, 10 Months, 10 Days old.</p>



// Example 4

echo '<p>Albert Einstein was on 2010-10-10 ', $birthday->getAge('2010-10-10'), ' years old.</p>';

// Result: <p>Albert Einstein was on 2010-10-10 131 years old.</p>



?>

tom at r dot je 10-Jun-2009 08:00


If you're stuck on a PHP 5.1 system (unfortunately one of my clients is on a rather horrible webhost who claims they cannot upgrade php) you can use this as a quick workaround:



<?php

if (!class_exists('DateTime')) {

class DateTime {

    public $date;

    

    public function __construct($date) {

        $this->date = strtotime($date);

    }

    

    public function setTimeZone($timezone) {

        return;

    }

    

    private function __getDate() {

        return date(DATE_ATOM, $this->date);    

    }

    

    public function modify($multiplier) {

        $this->date = strtotime($this->__getDate() . ' ' . $multiplier);

    }

    

    public function format($format) {

        return date($format, $this->date);

    }

}

}

?>



it is NOT perfect. Timezones and DST are not supported, but if you just need compatible basic functions this works. Feel free to complete this so it's compatible with the 5.2 datetime object.

add a note

The DateTime class

Introduction

Class synopsis

Predefined Constants

Changelog

Table of Contents