DateTime::format

DateTimeImmutable::format

DateTimeInterface::format

date_format

(PHP 5 >= 5.2.0, PHP 7)

DateTime::format -- DateTimeImmutable::format -- DateTimeInterface::format -- date_format — Returns date formatted according to given format

说明

面向对象风格

public string DateTime::format ( string $format )

public string DateTimeImmutable::format ( string $format )

public string DateTimeInterface::format ( string $format )

过程化风格

string date_format ( DateTimeInterface $object , string $format )

Returns date formatted according to given format.

参数

object: 仅为过程化风格：由 date_create() 返回的 DateTime 类型的对象。
format: Format accepted by date().

返回值

Returns the formatted date string on success 或者在失败时返回 FALSE.

范例

Example #1 DateTime::format() example

面向对象风格


<?php
$date = new DateTime('2000-01-01');
echo $date->format('Y-m-d H:i:s');
?>

过程化风格


<?php
$date = date_create('2000-01-01');
echo date_format($date, 'Y-m-d H:i:s');
?>

以上例程会输出：

2000-01-01 00:00:00

注释

This method does not use locales. All output is in English.

参见

date() - 格式化一个本地时间／日期

User Contributed Notes

prussell at cloudworksconsulting dot com 15-Sep-2014 09:02


The udate function is a great start, but the formatting of the milliseconds is a little off. If it is within the first 100000 microseconds then the string will be less than 6 characters, so 0.012435 will appear as 0.12345. The revision below fixes this.



function udate($strFormat = 'u', $uTimeStamp = null)

{



    // If the time wasn't provided then fill it in

    if (is_null($uTimeStamp))

    {

        $uTimeStamp = microtime(true);

    }



    // Round the time down to the second

    $dtTimeStamp = floor($uTimeStamp);



    // Determine the millisecond value

    $intMilliseconds = round(($uTimeStamp - $dtTimeStamp) * 1000000);

    // Format the milliseconds as a 6 character string

    $strMilliseconds = str_pad($intMilliseconds, 6, '0', STR_PAD_LEFT);



    // Replace the milliseconds in the date format string

    // Then use the date function to process the rest of the string

    return date(preg_replace('`(?<!\\\\)u`', $strMilliseconds, $strFormat), $dtTimeStamp);

}

soul dot enforcer at gmail dot com 02-Apr-2014 09:48


For full reference of the supported format character and results,

see the documentation of date() :

http://www.php.net/manual/en/function.date.php

chris at codewiz dot biz 13-Feb-2014 11:47


I believe this is a bug but its note-worthy if it is intended (I am using PHP 5.5.3).



$ php --version



PHP Warning:  Module 'xdebug' already loaded in Unknown on line 0

PHP 5.5.3-1ubuntu2.1 (cli) (built: Dec 12 2013 04:24:35) 

Copyright (c) 1997-2013 The PHP Group

Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies

    with Xdebug v2.2.3, Copyright (c) 2002-2013, by Derick Rethans

    with Zend OPcache v7.0.3-dev, Copyright (c) 1999-2013, by Zend Technologies



What is happening:



DateTime()->format() will modify the timezone. So do not expect the public date property to be returned (format mask applied) based on the current public timezone property. format will decide that when calling ->format() it will use the server timezone which eliminates all usefulness of ->setTimezone().



<?php

            $nowUtc = new \DateTime( 'now',  new \DateTimeZone( 'UTC' ) );

            echo '$nowUtc'.PHP_EOL;

            var_dump($nowUtc);

            $nowUtc = new \DateTime( 'now',  new \DateTimeZone( 'UTC' ) );

            echo '$nowUtc->format(\'Y-m-d h:i:s\')'.PHP_EOL;

            var_dump($nowUtc->format('Y-m-d h:i:s'));

            $nowUtc->setTimezone( new \DateTimeZone( 'Australia/Sydney' ) );

            echo '$nowUtc->setTimezone( new \DateTimeZone( \'Australia/Sydney\' ) )'.PHP_EOL;

            var_dump($nowUtc);

            echo '$nowUtc->format(\'Y-m-d h:i:s\')'.PHP_EOL;

            var_dump($nowUtc->format('Y-m-d h:i:s'));exit;

?>



outputs;



$nowUtc



object(DateTime)[2607]

  public 'date' => string '2014-02-13 02:42:48' (length=19)

  public 'timezone_type' => int 3

  public 'timezone' => string 'UTC' (length=3)



$nowUtc->format('Y-m-d h:i:s')



string '2014-02-13 02:42:48' (length=19)



$nowUtc->setTimezone( new \DateTimeZone( 'Australia/Sydney' ) )



object(DateTime)[2608]

  public 'date' => string '2014-02-13 13:42:48' (length=19)

  public 'timezone_type' => int 3

  public 'timezone' => string 'Australia/Sydney' (length=16)



$nowUtc->format('Y-m-d h:i:s')



string '2014-02-13 01:42:48' (length=19) // expected 2014-02-13 13:42:48 based on Australia/Sydney - what is 2014-02-13 01:42:48 from anyway!

daysnine at gmail dot com 04-Nov-2013 08:02


Seems like datetime::format does not really support microseconds as the documentation under date suggest it will.



Here is some code to generate a datetime with microseconds and timezone:



private function udate($format = 'u', $utimestamp = null) {

        if (is_null($utimestamp))

            $utimestamp = microtime(true);



        $timestamp = floor($utimestamp);

        $milliseconds = round(($utimestamp - $timestamp) * 1000000);



        return date(preg_replace('`(?<!\\\\)u`', $milliseconds, $format), $timestamp);

    }



echo udate('Y-m-d H:i:s.u T');

// Will output something like: 2014-01-01 12:20:24.42342 CET

craig dot constable at gmail dot com 02-Mar-2012 01:24


Using a datetime field from a mysql database e.g. "2012-03-24 17:45:12"



<?php



$result = mysql_query("SELECT `datetime` FROM `table`");

$row = mysql_fetch_row($result);

$date = date_create($row[0]);



echo date_format($date, 'Y-m-d H:i:s');

#output: 2012-03-24 17:45:12



echo date_format($date, 'd/m/Y H:i:s');

#output: 24/03/2012 17:45:12



echo date_format($date, 'd/m/y');

#output: 24/03/12



echo date_format($date, 'g:i A');

#output: 5:45 PM



echo date_format($date, 'G:ia');

#output: 05:45pm



echo date_format($date, 'g:ia \o\n l jS F Y');

#output: 5:45pm on Saturday 24th March 2012



?>

ca at agercon dot dk 01-Jul-2011 05:16


The date_format can be use to get the last day of February:



<?php 



function last_day_of_feb ($year) {

# The 0th day of a month is the same as the last day of the month before

        $ultimo_feb_str = $year . "-03-00"; 

        $ultimo_feb_date = date_create($ultimo_feb_str);

        $return = date_format($ultimo_feb_date, "Y-m-d");

        return $return;

}



echo last_day_of_feb(2011) . "\n"; # 2011-02-28

echo last_day_of_feb(2012) . "\n"; # 2011-02-29



?>