Date/Time 函数
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strftime

(PHP 4, PHP 5)

strftime — 根据区域设置格式化本地时间／日期

说明

string strftime ( string $format [, int $timestamp ] )

返回用给定的格式字串对给出的 timestamp 进行格式输出后的字符串。如果没有给出时间戳则用当前的本地时间。月份和星期几以及其它和语言有关的字符串写法和用 setlocale() 设定的当前的区域有关。

格式字串能识别下列转换标记：

Note:

可能不是所有的转换标记都被 C 库文件支持，这种情况下 PHP 的 strftime() 也不支持。此外，不是所有的平台都支持负的时间戳，因此日期的范围可能限定在不早于 Unix 纪元。这意味着例如 %e, %T，%R 和 %D（可能更多）以及早于 Jan 1, 1970 的时间在 Windows，一些 Linux 发行版本，以及其它几个操作系统中无效。对于 Windows 系统，所支持的转换标记可在 » MSDN 网站找到。

Example #1 strftime() 区域的例子

<?php
setlocale(LC_TIME, "C");
echo strftime("%A");
setlocale(LC_TIME, "fi_FI");
echo strftime(" in Finnish is %A,");
setlocale(LC_TIME, "fr_FR");
echo strftime(" in French %A and");
setlocale(LC_TIME, "de_DE");
echo strftime(" in German %A.\n");
?>
本例在你的系统中安装有各自的区域设置后才能工作。

Note: %G 和 %V，如果数字编号系统未能充分理解，基于 ISO 8601:1988 的星期数可能得出未预期的结果。见上面的 %V 和以下的例子。

Example #2 ISO 8601:1988 week number example

<?php
/*     December 2002 / January 2003
ISOWk  M   Tu  W   Thu F   Sa  Su
----- ----------------------------
51     16  17  18  19  20  21  22
52     23  24  25  26  27  28  29
1      30  31   1   2   3   4   5
2       6   7   8   9  10  11  12
3      13  14  15  16  17  18  19   */

// Outputs: 12/28/2002 - %V,%G,%Y = 52,2002,2002
echo "12/28/2002 - %V,%G,%Y = " . strftime("%V,%G,%Y", strtotime("12/28/2002")) . "\n";

// Outputs: 12/30/2002 - %V,%G,%Y = 1,2003,2002
echo "12/30/2002 - %V,%G,%Y = " . strftime("%V,%G,%Y", strtotime("12/30/2002")) . "\n";

// Outputs: 1/3/2003 - %V,%G,%Y = 1,2003,2003
echo "1/3/2003 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/3/2003")) . "\n";

// Outputs: 1/10/2003 - %V,%G,%Y = 2,2003,2003
echo "1/10/2003 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/10/2003")) . "\n";



/*     December 2004 / January 2005
ISOWk  M   Tu  W   Thu F   Sa  Su
----- ----------------------------
51     13  14  15  16  17  18  19
52     20  21  22  23  24  25  26
53     27  28  29  30  31   1   2
1       3   4   5   6   7   8   9
2      10  11  12  13  14  15  16   */

// Outputs: 12/23/2004 - %V,%G,%Y = 52,2004,2004
echo "12/23/2004 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("12/23/2004")) . "\n";

// Outputs: 12/31/2004 - %V,%G,%Y = 53,2004,2004
echo "12/31/2004 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("12/31/2004")) . "\n";

// Outputs: 1/2/2005 - %V,%G,%Y = 53,2004,2005
echo "1/2/2005 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/2/2005")) . "\n";

// Outputs: 1/3/2005 - %V,%G,%Y = 1,2005,2005
echo "1/3/2005 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/3/2005")) . "\n";

?>

参见 setlocale()，mktime()，strptime() 以及 » Open Group specification of strftime()。

参数

format

The following characters are recognized in the format parameter string
format Description Example returned values
Day --- ---
%a An abbreviated textual representation of the day Sun through Sat
%A A full textual representation of the day Sunday through Saturday
%d Two-digit day of the month (with leading zeros) 01 to 31
%e Day of the month, with a space preceding single digits. Not implemented as described on Windows. See below for more information. 1 to 31
%j Day of the year, 3 digits with leading zeros 001 to 366
%u ISO-8601 numeric representation of the day of the week 1 (for Monday) though 7 (for Sunday)
%w Numeric representation of the day of the week 0 (for Sunday) through 6 (for Saturday)
Week --- ---
%U Week number of the given year, starting with the first Sunday as the first week 13 (for the 13th full week of the year)
%V ISO-8601:1988 week number of the given year, starting with the first week of the year with at least 4 weekdays, with Monday being the start of the week 01 through 53 (where 53 accounts for an overlapping week)
%W A numeric representation of the week of the year, starting with the first Monday as the first week 46 (for the 46th week of the year beginning with a Monday)
Month --- ---
%b Abbreviated month name, based on the locale Jan through Dec
%B Full month name, based on the locale January through December
%h Abbreviated month name, based on the locale (an alias of %b) Jan through Dec
%m Two digit representation of the month 01 (for January) through 12 (for December)
Year --- ---
%C Two digit representation of the century (year divided by 100, truncated to an integer) 19 for the 20th Century
%g Two digit representation of the year going by ISO-8601:1988 standards (see %V) Example: 09 for the week of January 6, 2009
%G The full four-digit version of %g Example: 2008 for the week of January 3, 2009
%y Two digit representation of the year Example: 09 for 2009, 79 for 1979
%Y Four digit representation for the year Example: 2038
Time --- ---
%H Two digit representation of the hour in 24-hour format 00 through 23
%I Two digit representation of the hour in 12-hour format 01 through 12
%l (lower-case 'L') Hour in 12-hour format, with a space preceeding single digits 1 through 12
%M Two digit representation of the minute 00 through 59
%p UPPER-CASE 'AM' or 'PM' based on the given time Example: AM for 00:31, PM for 22:23
%P lower-case 'am' or 'pm' based on the given time Example: am for 00:31, pm for 22:23
%r Same as "%I:%M:%S %p" Example: 09:34:17 PM for 21:34:17
%R Same as "%H:%M" Example: 00:35 for 12:35 AM, 16:44 for 4:44 PM
%S Two digit representation of the second 00 through 59
%T Same as "%H:%M:%S" Example: 21:34:17 for 09:34:17 PM
%X Preferred time representation based on locale, without the date Example: 03:59:16 or 15:59:16
%z Either the time zone offset from UTC or the abbreviation (depends on operating system) Example: -0500 or EST for Eastern Time
%Z The time zone offset/abbreviation option NOT given by %z (depends on operating system) Example: -0500 or EST for Eastern Time
Time and Date Stamps --- ---
%c Preferred date and time stamp based on local Example: Tue Feb 5 00:45:10 2009 for February 5, 2009 at 12:45:10 AM
%D Same as "%m/%d/%y" Example: 02/05/09 for February 5, 2009
%F Same as "%Y-%m-%d" (commonly used in database datestamps) Example: 2009-02-05 for February 5, 2009
%s Unix Epoch Time timestamp (same as the time() function) Example: 305815200 for September 10, 1979 08:40:00 AM
%x Preferred date representation based on locale, without the time Example: 02/05/09 for February 5, 2009
Miscellaneous --- ---
%n A newline character ("\n") ---
%t A Tab character ("\t") ---
%% A literal percentage character ("%") ---

Maximum length of this parameter is 1023 characters.

Warning

Contrary to ISO-9899:1999, Sun Solaris starts with Sunday as 1. As a result, %u may not function as described in this manual.

Warning

Windows only: The %e modifier is not supported in the Windows implementation of this function. To achieve this value, the %#d modifier can be used instead. The example below illustrates how to write a cross platform compatible function.

Warning

Mac OS X only: The %P modifier is not supported in the Mac OS X implementation of this function.

timestamp

可选的 timestamp 参数是一个 integer 的 Unix 时间戳，如未指定，参数值默认为当前本地时间。也就是说，其值默认为 time() 的返回值。

返回值

Returns a string formatted according format using the given timestamp or the current local time if no timestamp is given. Month and weekday names and other language-dependent strings respect the current locale set with setlocale().

错误/异常

在每 次调用日期/时间函数时，如果时区无效则会引发 E_NOTICE 错误，如果使用系统设定值或 TZ 环境变量，则会引发 E_STRICT 或 E_WARNING 消息。参见 date_default_timezone_set()

As the output is dependent upon the underlying C library, some conversion specifiers are not supported. On Windows, supplying unknown conversion specifiers will result in 5 E_WARNING messages and return FALSE. On other operating systems you may not get any E_WARNING messages and the output may contain the conversion specifiers unconverted.

更新日志

版本 说明
5.1.0

现在发布 E_STRICT 和 E_NOTICE 时区错误。

范例

This example will work if you have the respective locales installed in your system.

Example #3 strftime() locale examples

<?php
setlocale(LC_TIME, "C");
echo strftime("%A");
setlocale(LC_TIME, "fi_FI");
echo strftime(" in Finnish is %A,");
setlocale(LC_TIME, "fr_FR");
echo strftime(" in French %A and");
setlocale(LC_TIME, "de_DE");
echo strftime(" in German %A.\n");
?>

Example #4 ISO 8601:1988 week number example

<?php
/*     December 2002 / January 2003
ISOWk  M   Tu  W   Thu F   Sa  Su
----- ----------------------------
51     16  17  18  19  20  21  22
52     23  24  25  26  27  28  29
1      30  31   1   2   3   4   5
2       6   7   8   9  10  11  12
3      13  14  15  16  17  18  19   */

// Outputs: 12/28/2002 - %V,%G,%Y = 52,2002,2002
echo "12/28/2002 - %V,%G,%Y = " . strftime("%V,%G,%Y", strtotime("12/28/2002")) . "\n";

// Outputs: 12/30/2002 - %V,%G,%Y = 1,2003,2002
echo "12/30/2002 - %V,%G,%Y = " . strftime("%V,%G,%Y", strtotime("12/30/2002")) . "\n";

// Outputs: 1/3/2003 - %V,%G,%Y = 1,2003,2003
echo "1/3/2003 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/3/2003")) . "\n";

// Outputs: 1/10/2003 - %V,%G,%Y = 2,2003,2003
echo "1/10/2003 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/10/2003")) . "\n";



/*     December 2004 / January 2005
ISOWk  M   Tu  W   Thu F   Sa  Su
----- ----------------------------
51     13  14  15  16  17  18  19
52     20  21  22  23  24  25  26
53     27  28  29  30  31   1   2
1       3   4   5   6   7   8   9
2      10  11  12  13  14  15  16   */

// Outputs: 12/23/2004 - %V,%G,%Y = 52,2004,2004
echo "12/23/2004 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("12/23/2004")) . "\n";

// Outputs: 12/31/2004 - %V,%G,%Y = 53,2004,2004
echo "12/31/2004 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("12/31/2004")) . "\n";

// Outputs: 1/2/2005 - %V,%G,%Y = 53,2004,2005
echo "1/2/2005 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/2/2005")) . "\n";

// Outputs: 1/3/2005 - %V,%G,%Y = 1,2005,2005
echo "1/3/2005 - %V,%G,%Y = " . strftime("%V,%G,%Y",strtotime("1/3/2005")) . "\n";

?>

Example #5 Cross platform compatible example using the %e modifier

<?php

// Jan 1: results in: '%e%1%' (%%, e, %%, %e, %%)
$format = '%%e%%%e%%';

// Check for Windows to find and replace the %e 
// modifier correctly
if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN') {
    $format = preg_replace('#(?<!%)((?:%%)*)%e#', '</refsect1>%#d', $format);
}

echo strftime($format);
?>

Example #6 Display all known and unknown formats.

<?php
// Describe the formats.
$strftimeFormats = array(
    'A' => 'A full textual representation of the day',
    'B' => 'Full month name, based on the locale',
    'C' => 'Two digit representation of the century (year divided by 100, truncated to an integer)',
    'D' => 'Same as "%m/%d/%y"',
    'E' => '',
    'F' => 'Same as "%Y-%m-%d"',
    'G' => 'The full four-digit version of %g',
    'H' => 'Two digit representation of the hour in 24-hour format',
    'I' => 'Two digit representation of the hour in 12-hour format',
    'J' => '',
    'K' => '',
    'L' => '',
    'M' => 'Two digit representation of the minute',
    'N' => '',
    'O' => '',
    'P' => 'lower-case "am" or "pm" based on the given time',
    'Q' => '',
    'R' => 'Same as "%H:%M"',
    'S' => 'Two digit representation of the second',
    'T' => 'Same as "%H:%M:%S"',
    'U' => 'Week number of the given year, starting with the first Sunday as the first week',
    'V' => 'ISO-8601:1988 week number of the given year, starting with the first week of the year with at least 4 weekdays, with Monday being the start of the week',
    'W' => 'A numeric representation of the week of the year, starting with the first Monday as the first week',
    'X' => 'Preferred time representation based on locale, without the date',
    'Y' => 'Four digit representation for the year',
    'Z' => 'The time zone offset/abbreviation option NOT given by %z (depends on operating system)',
    'a' => 'An abbreviated textual representation of the day',
    'b' => 'Abbreviated month name, based on the locale',
    'c' => 'Preferred date and time stamp based on local',
    'd' => 'Two-digit day of the month (with leading zeros)',
    'e' => 'Day of the month, with a space preceding single digits',
    'f' => '',
    'g' => 'Two digit representation of the year going by ISO-8601:1988 standards (see %V)',
    'h' => 'Abbreviated month name, based on the locale (an alias of %b)',
    'i' => '',
    'j' => 'Day of the year, 3 digits with leading zeros',
    'k' => '',
    'l' => 'Hour in 12-hour format, with a space preceeding single digits',
    'm' => 'Two digit representation of the month',
    'n' => 'A newline character ("\n")',
    'o' => '',
    'p' => 'UPPER-CASE "AM" or "PM" based on the given time',
    'q' => '',
    'r' => 'Same as "%I:%M:%S %p"',
    's' => 'Unix Epoch Time timestamp',
    't' => 'A Tab character ("\t")',
    'u' => 'ISO-8601 numeric representation of the day of the week',
    'v' => '',
    'w' => 'Numeric representation of the day of the week',
    'x' => 'Preferred date representation based on locale, without the time',
    'y' => 'Two digit representation of the year',
    'z' => 'Either the time zone offset from UTC or the abbreviation (depends on operating system)',
    '%' => 'A literal percentage character ("%")',
);

// Results.
$strftimeValues = array();

// Evaluate the formats whilst suppressing any errors.
foreach($strftimeFormats as $format => $description){
    if (False !== ($value = @strftime("%{$format}"))){
        $strftimeValues[$format] = $value;
    }
}

// Find the longest value.
$maxValueLength = 2 + max(array_map('strlen', $strftimeValues));

// Report known formats.
foreach($strftimeValues as $format => $value){
    echo "Known format   : '{$format}' = ", str_pad("'{$value}'", $maxValueLength), " ( {$strftimeFormats[$format]} )\n";
}

// Report unknown formats.
foreach(array_diff_key($strftimeFormats, $strftimeValues) as $format => $description){
    echo "Unknown format : '{$format}'   ", str_pad(' ', $maxValueLength), ($description ? " ( {$description} )" : ''), "\n";
}
?>

以上例程的输出类似于：

Known format   : 'A' = 'Friday'            ( A full textual representation of the day )
Known format   : 'B' = 'December'          ( Full month name, based on the locale )
Known format   : 'H' = '11'                ( Two digit representation of the hour in 24-hour format )
Known format   : 'I' = '11'                ( Two digit representation of the hour in 12-hour format )
Known format   : 'M' = '24'                ( Two digit representation of the minute )
Known format   : 'S' = '44'                ( Two digit representation of the second )
Known format   : 'U' = '48'                ( Week number of the given year, starting with the first Sunday as the first week )
Known format   : 'W' = '48'                ( A numeric representation of the week of the year, starting with the first Monday as the first week )
Known format   : 'X' = '11:24:44'          ( Preferred time representation based on locale, without the date )
Known format   : 'Y' = '2010'              ( Four digit representation for the year )
Known format   : 'Z' = 'GMT Standard Time' ( The time zone offset/abbreviation option NOT given by %z (depends on operating system) )
Known format   : 'a' = 'Fri'               ( An abbreviated textual representation of the day )
Known format   : 'b' = 'Dec'               ( Abbreviated month name, based on the locale )
Known format   : 'c' = '12/03/10 11:24:44' ( Preferred date and time stamp based on local )
Known format   : 'd' = '03'                ( Two-digit day of the month (with leading zeros) )
Known format   : 'j' = '337'               ( Day of the year, 3 digits with leading zeros )
Known format   : 'm' = '12'                ( Two digit representation of the month )
Known format   : 'p' = 'AM'                ( UPPER-CASE "AM" or "PM" based on the given time )
Known format   : 'w' = '5'                 ( Numeric representation of the day of the week )
Known format   : 'x' = '12/03/10'          ( Preferred date representation based on locale, without the time )
Known format   : 'y' = '10'                ( Two digit representation of the year )
Known format   : 'z' = 'GMT Standard Time' ( Either the time zone offset from UTC or the abbreviation (depends on operating system) )
Known format   : '%' = '%'                 ( A literal percentage character ("%") )
Unknown format : 'C'                       ( Two digit representation of the century (year divided by 100, truncated to an integer) )
Unknown format : 'D'                       ( Same as "%m/%d/%y" )
Unknown format : 'E'
Unknown format : 'F'                       ( Same as "%Y-%m-%d" )
Unknown format : 'G'                       ( The full four-digit version of %g )
Unknown format : 'J'
Unknown format : 'K'
Unknown format : 'L'
Unknown format : 'N'
Unknown format : 'O'
Unknown format : 'P'                       ( lower-case "am" or "pm" based on the given time )
Unknown format : 'Q'
Unknown format : 'R'                       ( Same as "%H:%M" )
Unknown format : 'T'                       ( Same as "%H:%M:%S" )
Unknown format : 'V'                       ( ISO-8601:1988 week number of the given year, starting with the first week of the year with at least 4 weekdays, with Monday being the start of the week )
Unknown format : 'e'                       ( Day of the month, with a space preceding single digits )
Unknown format : 'f'
Unknown format : 'g'                       ( Two digit representation of the year going by ISO-8601:1988 standards (see %V) )
Unknown format : 'h'                       ( Abbreviated month name, based on the locale (an alias of %b) )
Unknown format : 'i'
Unknown format : 'k'
Unknown format : 'l'                       ( Hour in 12-hour format, with a space preceeding single digits )
Unknown format : 'n'                       ( A newline character ("\n") )
Unknown format : 'o'
Unknown format : 'q'
Unknown format : 'r'                       ( Same as "%I:%M:%S %p" )
Unknown format : 's'                       ( Unix Epoch Time timestamp )
Unknown format : 't'                       ( A Tab character ("\t") )
Unknown format : 'u'                       ( ISO-8601 numeric representation of the day of the week )
Unknown format : 'v'

注释

Note: %G and %V, which are based on ISO 8601:1988 week numbers can give unexpected (albeit correct) results if the numbering system is not thoroughly understood. See %V examples in this manual page.

参见

Date/Time 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 根据区域设置格式化本地时间／日期

用户评论:

Chris (12-Aug-2011 09:37)

Sometimes, you want Jan 1 to be week 1 and weeks to begin on Sunday. Here's a way to use strftime U format character to follow this convention:
<?php
$month = 5; $year = 2012; echo "Week #'s in May 2012: ";
$week_num_correction = strftime('%U', mktime(0,0,0,1,1,$year)) === '00' ? 1 : 0;
$week_numbers = range(strftime('%U', mktime(0,0,0,$month,1,$year)) + $week_num_correction, strftime('%U', mktime(0,0,0,$month+1,0,$year)) + $week_num_correction);
foreach($week_numbers as $week_number) echo "$week_number ";
?>
displays: Week #'s in May 2012: 18 19 20 21 22

fmaz008 at gmail dot com (09-Aug-2011 08:50)

The example of the workarround for the %e modifier is a bit complex. Sometime you might want to prefer a simple ltrim():

<?php
ltrim(strftime('%d', $time), '0');
?>

dgudgeon at example dot com (14-Jul-2011 01:04)

If moving from date() to strftime() to support additional languages, you may miss the ordinal suffix format option date('S'). Workaround this by adding an extra modifier (%O).

<?php
function my_strftime ($format, $timestamp)
{
    $format = str_replace('%O', date('S', $timestamp), $format);   
    return strftime($format, $timestamp);
}
?>

Bondas Timotei (19-May-2011 12:41)

If strange characters are returned use utf8_encode(strftime()) for UTF-8 characters

ciprianmp at yahoo dot com (13-Feb-2011 09:04)

This worked for me to distinguish between windows and linux, for stripping leading zeros from days/months in the short formats (like for Czech):
stristr(PHP_OS,"win") ? "%#d.%#m.%Y" : "%-d.%-m.%Y"

Anonymous (12-Oct-2010 08:04)

%V may fail with some systems (Windows XP, at least). Here is a function that should work to get the week number of a day (timestamped), according to ISO 8601.

"should work" as in "it is working with my understanding of this norm", where 1st of january can be week 52, 53 or 01. Hopefully.

testing (php_uname("s") == "Windows NT") or equivalent can be an option (when switching between Wampserver and a GNU server, for instance).

Please, erase and correct my message if there is any error.

<?php
function week_isonumber ($time) {
// When strftime("%V") fails, some unoptimized workaround
//
// http://en.wikipedia.org/wiki/ISO_8601 : week 1 is "the week with the year's first Thursday in it (the formal ISO definition)"

    $year = strftime("%Y", $time);

    $first_day = strftime("%w", mktime(0, 0, 0, 1, 1, $year));
    $last_day = strftime("%w", mktime(0, 0, 0, 12, 31, $year));
       
    $number = $isonumber = strftime("%W", $time);

    // According to strftime("%W"), 1st of january is in week 1 if and only if it is a monday
    if ($first_day == 1)
        $isonumber--;

    // 1st of january is between monday and thursday; starting (now) at 0 when it should be 1
    if ($first_day >= 1 && $first_day <= 4)
        $isonumber++;
    else if ($number == 0)
        $isonumber = week_isonumber(mktime(0, 0, 0, 12, 31, $year - 1));

    if ($isonumber == 53 && ($last_day == 1 || $last_day == 2 || $last_day == 3))
        $isonumber = 1;

    return sprintf("%02d", $isonumber);
}
?>

Lemmi (09-Jun-2010 01:57)

Why not use utf8_encode to fix problems with letters in ISO-8859-1 and charset set to UTF-8?

For example:
<?php

setlocale(LC_TIME, "de_DE");
echo utf8_encode(strftime('%B')); // Output e.g.: M?rz

?>

cyrille37 at gmail dot com (05-May-2010 01:12)

The format "%e" does not work on Windows.
There is a bug entry : http://bugs.php.net/bug.php?id=45847

It's because strftime is not portable, it use the operating system function.
For Win32, to get more documentation we have to consult the Windows "Run-Time Library Reference" for strftime :
http://msdn.microsoft.com/en-us/library/fe06s4ak%28VS.71%29.aspx

And we can find the solution:
  replace "%e" by "%#d"
the "#" remove leading zeros (if any).

Cyrille

baptiste dot place at utopiaweb dot fr (26-Feb-2010 12:54)

Created this small method to convert a date format to a strftime format. One format is enough to learn :)

<?php
/**
 * Convert a date format to a strftime format
 *
 * Timezone conversion is done for unix. Windows users must exchange %z and %Z.
 *
 * Unsupported date formats : S, n, t, L, B, G, u, e, I, P, Z, c, r
 * Unsupported strftime formats : %U, %W, %C, %g, %r, %R, %T, %X, %c, %D, %F, %x
 *
 * @param string $dateFormat a date format
 * @return string
 */
public static function dateFormatToStrftime($dateFormat) {
   
    $caracs = array(
        // Day - no strf eq : S
        'd' => '%d', 'D' => '%a', 'j' => '%e', 'l' => '%A', 'N' => '%u', 'w' => '%w', 'z' => '%j',
        // Week - no date eq : %U, %W
        'W' => '%V', 
        // Month - no strf eq : n, t
        'F' => '%B', 'm' => '%m', 'M' => '%b',
        // Year - no strf eq : L; no date eq : %C, %g
        'o' => '%G', 'Y' => '%Y', 'y' => '%y',
        // Time - no strf eq : B, G, u; no date eq : %r, %R, %T, %X
        'a' => '%P', 'A' => '%p', 'g' => '%l', 'h' => '%I', 'H' => '%H', 'i' => '%M', 's' => '%S',
        // Timezone - no strf eq : e, I, P, Z
        'O' => '%z', 'T' => '%Z',
        // Full Date / Time - no strf eq : c, r; no date eq : %c, %D, %F, %x 
        'U' => '%s'
    );
   
    return strtr((string)$dateFormat, $caracs);
}
?>

I use it with this condition on a date format :
if(preg_match("/(D|l|F|M)/", $format))

sasha at goldnet dot ca (09-Jan-2010 02:54)

You can remove leading "0" from %m (two digit representation of the month) by using "-".
%-m  => Month of the year (1 to 12) without leading zero

Chad (11-Nov-2009 01:50)

On the Linux server I'm using, strftime() also accepts a "-" option to request no padding:

<?php
$ts = strtotime("4 Nov 2009");
echo strlen(strftime("%-e", $ts)), "\n"; // "1" (no padding)
echo strlen(strftime("%e", $ts)), "\n"; // "2" (space padded)
?>

szilagyigabor at yahoo dot com (02-Nov-2009 07:43)

This is that worked with UTF-8 encoding on Linux server, with right accents:
<?php
setlocale(LC_ALL, 'hu_HU.UTF8');
echo(strftime('%Y. %B %d. %A'));
?>

Output is:
2009. november 02. hétf?

Also, this one can be used, if not utf-8 preferred:
<?php
setlocale(LC_ALL, 'hu_HU.ISO8859-2');
?>

UTF-8 is not supported on windows platforms, so there the iconv workaround must be used:
<?php
setlocale(LC_ALL, 'hun_hun');
echo(iconv('ISO-8859-2', 'UTF-8',strftime('%Y. %B %d. %A')));
?>

The output is the same as before. Note that, the iconv first parameter is ISO-8859-2 not ISO-8859-1, because the locale is hungarian which uses 8859-2 codepage as default. It is needed for the right accents.

If you want use the same code for Windows and Linux platforms, the second one is the right option (the iconv trick), but the locale configuration must be different (Linux: hu_HU, windows: hun_hun), but in that case the UTF8 tag is not needed for the Linux config.

jjarsater at gmail dot com (20-May-2009 03:01)

<?php
// Date string
$timestamp     =     strftime("%Y-%m-%d %H:%M:%S %Y");

// From this string ($timestamp) can we print
echo strftime("%a %d %b %H:%M:%S %Y", strtotime($timestamp))."<br/>";
echo strftime("%a %d %b %H:%M", strtotime($timestamp))."<br/>";
echo strftime("%Y-%m-%d %H:%M:%S", strtotime($timestamp))."<br/>";
echo strftime("%Y-%m-%d %H:%M", strtotime($timestamp))."<br/>";
echo strftime("%Y-%m-%d", strtotime($timestamp))."<br/>";
echo strftime("%a %d %b %Y", strtotime($timestamp))."<br/>";

/*And it will output

Wed 20 May 15:53:40 2009
Wed 20 May 15:53
2009-05-20 15:53:40
2009-05-20 15:53
2009-05-20
Wed 20 May 2009

*/
?>

Michael Z. (18-May-2009 11:12)

This is so simple it has to be found in one of all the comments on all those different time functions. But since I didn't find it, here it is: Use this to convert between different time formats:

<?PHP
if (!function_exists('convertTime')) {
  /** Converts time strings from one format into another using
   *  PHP formats.
   *
   *  @param String $dformat Format to convert to
   *  @param String $sformat Format to convert from, e.g. format
   *      of $ts
   *  @param String $ts Time string to be converted
   *  @return String Supplied time translated to the format specified
   *    in $dformat
   */
  function convertTime($dformat,$sformat,$ts) {
    extract(strptime($ts,$sformat));
    return strftime($dformat,mktime(
                                  intval($tm_hour),
                                  intval($tm_min),
                                  intval($tm_sec),
                                  intval($tm_mon)+1,
                                  intval($tm_mday),
                                  intval($tm_year)+1900
                                ));
  }
}

/*
 * And for the test....
 */
echo convertTime('%Y-%m-%d','%d.%m.%Y','27.11.2009');
?>

This should print "2009-27-11".

I did not put much effort in this code. The task also seems "too simple to be neccessary". But as I said, I didn't find anything to help me with this.

Cheers,

Michael Z

dapikk[at]gmail[dot]com (16-Mar-2009 10:21)

I had a need to subtrackt an older time from current time to get the time between.
Example: If one has worked from 2009-03-16 11:33:54 to 2009-03-16 12:01:54 then he has worked X hours,minutes and seconds. I tried to find that X. And so - one solution would be:
<?php
$start_date = strtotime("2009-03-16 11:33:54"); //start date from database - date("Y-m-d H:i:s") made as UNIX timestamp
$end_date = strtotime("2009-03-16 12:01:54"); //end date from database - date("Y-m-d H:i:s") made as UNIX timestamp
$ajavahe = $end_date - $start_date;
$time_between = gmstrftime('%Hh %Mm %Ss', $ajavahe); //gmstrftime() deals with different timezones correctly. (If in example you would be situated in Estonia and you would use strftime() you get wrong answer off by 2 hrs, because timezone is GMT+2 - with gmstrftime() comes right answer.)

echo 'You have worked: '.$time_between;
?>
Hope that this one makes someones life easier :D

lamb dot dan at gmail dot com (04-Dec-2008 06:37)

<?php
/*
*    This function figures out what fiscal year a specified date is in.
*    $inputDate - the date you wish to find the fiscal year for. (12/4/08)
*    $fyStartDate - the month and day your fiscal year starts. (7/1)
*    $fyEndDate - the month and day your fiscal year ends. (6/30)
*    $fy - returns the correct fiscal year
*/
function calculateFiscalYearForDate($inputDate, $fyStart, $fyEnd){
    $date = strtotime($inputDate);
    $inputyear = strftime('%Y',$date);
       
    $fystartdate = strtotime($fyStart.$inputyear);
    $fyenddate = strtotime($fyEnd.$inputyear);

    if($date < $fyenddate){
        $fy = intval($inputyear);
    }else{
        $fy = intval(intval($inputyear) + 1);
    }
   
    return $fy;
   
}

// my fiscal year starts on July,1 and ends on June 30, so...
echo calculateFiscalYearForDate("5/15/08","7/1","6/30");
// returns 2008

echo calculateFiscalYearForDate("12/1/08","7/1","6/30");
// returns 2009
?>

khaled dot ataia at gmail dot com (05-Nov-2008 02:24)

for Arabic

<?php
setlocale(LC_ALL,'ar');
echo strftime('%A %d %B %Y');
?>

eljaunis at gmail dot com (22-Oct-2008 11:33)

This is what worked in my case:

<?php
    setlocale(LC_ALL, 'es_ES').': ';
    echo iconv('ISO-8859-1', 'UTF-8', strftime('%A %d de %B de %Y', time()));
    ?>

it displays: miércoles 22 de octubre de 2008

buana95 at yahoo dot com (21-Aug-2008 04:51)

For windows user:

If you unsuccessfully change date/time format to your locale country using xx_XX format, try using XXX format or ISO-639 country codes format.

See complete list for ISO-639 here: http://www.w3.org/WAI/ER/IG/ert/iso639.htm

For example:

<?php
setlocale(LC_ALL, 'IND');
echo strftime("Today in Indonesia is %A");
?>

Josue R. (09-Mar-2008 03:36)

Here's a simple version for date formating i use between displaying in HTML and converting back to MYSQL format:

<?php
function format_date($original='', $format="%m/%d/%Y") {
    $format = ($format=='date' ? "%m-%d-%Y" : $format);
    $format = ($format=='datetime' ? "%m-%d-%Y %H:%M:%S" : $format);
    $format = ($format=='mysql-date' ? "%Y-%m-%d" : $format);
    $format = ($format=='mysql-datetime' ? "%Y-%m-%d %H:%M:%S" : $format);
    return (!empty($original) ? strftime($format, strtotime($original)) : "" );
}
?>

example (in HTML or webapp):
[grab from database]...
$dbase_stored_date = "2007-03-15";
$display_html_date = format_date($dbase_stored_date);
... displays as "03/15/2007"

example (saving form via on POST/GET):
$update_date = format_date($_POST['display_html_date'], 'mysql-date');
// converts back to '2007-03-15'
.... [your mysql update here]

Don't forget to sanitize your POST/GET's   =)

jerome dot place at free dot fr (07-Nov-2007 08:55)

Here is a function to convert dates before 1970, very useful if you are still using php 4 (it is supported in php5) :

<?php
# convert a date to special format
# $date is like 2000-01-01 00:00:00
# $format : refer to strftime function
function convert_date($date,$format) {   
    if($date=='0000-00-00 00:00:00' OR $date=='0000-00-00' OR $date=='' OR $date==NULL) {
        return '';
    }
    else {
        $year=substr($date,0,4);
        if(phpversion() < 5.0 AND $year < 1970) {
           
            $new_date=substr_replace($date,'1980',0,4); # we replace the year by a year after 1970       
            $new_format=eregi_replace('%a|%A|%u','',$format); # we remove days information from the format because they would be wrong
            $new_date=strftime($new_format,strtotime($new_date)); # we convert the date
            $new_date=eregi_replace('1980',$year,$new_date); # we put back the real year
            return $new_date;
        }
        else {
            return strftime($format,strtotime($date));
        }
    }
}
?>

nielsvan den berge at hotmail dot com (31-Aug-2007 02:43)

A small function to get the first weekday of the month.
For example the first monday of the month, or the first friday, etc.

<?php 
  /**
   *
   *  Gets the first weekday of that month and year
   *
   *  @param  int   The day of the week (0 = sunday, 1 = monday ... , 6 = saturday)
   *  @param  int   The month (if false use the current month)
   *  @param  int   The year (if false use the current year)
   *
   *  @return int   The timestamp of the first day of that month
   *
   **/ 
  function get_first_day($day_number=1, $month=false, $year=false)
  {
    $month  = ($month === false) ? strftime("%m"): $month;
    $year   = ($year === false) ? strftime("%Y"): $year;
   
    $first_day = 1 + ((7+$day_number - strftime("%w", mktime(0,0,0,$month, 1, $year)))%7);
 
    return mktime(0,0,0,$month, $first_day, $year);
  }

// this will output the first wednesday of january 2007 (wed 03-01-2007)
echo strftime("%a %d-%m-%Y", get_first_day(3, 1, 2007));
?>

ma (28-Aug-2007 01:58)

note, that for some languages you MUST set LC_ALL instead of LC_TIME.

note that you further have to explicitly define your output-encoding (default is ISO-8859-1 [which makes problems for some languages])!

at least i expirienced this behaviour on a german WinXP-PHP4 environment:

<?php

// does not work - gives question marks:
setlocale(LC_TIME, 'RUS'); // ISO Alpha-3 is supported by xp
echo strftime('%A', time());

?>

<?php

// DOES work:
header('Content-Type: text/html; charset=UTF-8'); // you could also use another charset here if iconv isn't installed on your system.

echo setlocale(LC_ALL, 'RUS').': ';
echo iconv('windows-1251', 'UTF-8', strftime('%A', time()))."\n";

?>

ben dot holland at thirdlight dot com (21-Jun-2007 01:03)

This little function allows you to provide a reasonably human readable string and convert to a timestamp - see example in comments below.

I find it far more useful than having to remember all the '%' modifiers. Am also well aware of its failings but it works in a lot of the real life situations I've come across.

<?php
function AmazingStringFromTime($str, $nTimestamp = null)
{
    // This function reads a human readable string representation of dates. e.g.
    // DD MM YYYY => 01 07 1978
    // DDD D MMM YY => Mon 1 Jul 78
   
    $arrPairs = array(
    "DDDD"  => "%A",
    "DDD"   => "%a",
    "DD"    => "%d",
    "D"     => "%e", // has leading space: ' 1', ' 2', etc for single digit days
    "MMMM"  => "%B",
    "MMM"   => "%b",
    "MM"    => "%m",
    "YYYY"  => "%Y",
    "YY"    => "%y",
    "HH"    => "%H",
    "hh"    => "%I",
    "mm"    => "%M",
    "ss"    => "%S",
    );
   
    $str = str_replace(array_keys($arrPairs), array_values($arrPairs), $str);
    return strftime($str, $nTimestamp);
}
?>

th1nk3r at gmail dot DELETETHIS dot com (20-Jan-2007 05:35)

Function strftime() use the locales installed in your system (linux).

If you are like me and only leave in the system the locales you use normally (en_US and your own language locale, like es_ES), you'll only be able to use the locales installed. If your application is translated to other languages, you need these locales too.

The name of the locale in your system is important too. This can be a problem when you want to distribute the app.

If you have this locales in your system:
en_US/ISO-8859-1
en_US.UTF-8/UTF-8
es_ES/ISO-8859-1
es_ES@euro/ISO-8859-15
es_ES.UTF-8/UTF-8
es_ES@euro/UTF-8

and use setlocale('es_ES'), the result will use the iso-8859-1 charset even if you have all your system, files and configuration options in UTF-8. To receive content in UTF-8, in this example, you need to use setlocale('es_ES.UTF-8') or setlocale('es_ES.UTF-8@UTF-8').

The definition of locales can change from one system to another, and so the charset from the results.

denis at spiralsolutions dot com (02-Nov-2006 08:07)

(in addition to Andy's post)
To get a RFC 2822 date (used in RSS) of the current local time :

echo strftime ("%a, %d %b %Y %H:%M:%S %z") ;

Note: option %z / %Z - work different on Windows platform, for example
output of this code line can be:
Thu, 02 Nov 2006 09:54:59 Jerusalem Standard Time (on Windows)
Thu, 02 Nov 2006 09:54:59 +0200                   (on Linux)

[red. It is much smarter to use date(DATE_RSS); here]

Jon Keating (18-Jan-2006 01:49)

Under windows if you are using Japanese version, you must use the following code:

setlocale(LC_ALL, "Japanese_Japan.20932") for EUC
setlocale(LC_ALL, "Japanese_Japan.932") for SJIS

I found the following page that helped me with this issue:
http://moodle.org/mod/forum/discuss.php?d=8329

jw at jwscripts dot com (29-May-2005 02:32)

The following function implements the conversion specifiers which are not supported on Win32 platforms:

(Note: the specifiers %V, %G and %g can be implemented using other functions described in this section)

<?php

function strftime_win32($format, $ts = null) {
    if (!$ts) $ts = time();

    $mapping = array(
        '%C' => sprintf("%02d", date("Y", $ts) / 100),
        '%D' => '%m/%d/%y',
        '%e' => sprintf("%' 2d", date("j", $ts)),
        '%h' => '%b',
        '%n' => "\n",
        '%r' => date("h:i:s", $ts) . " %p",
        '%R' => date("H:i", $ts),
        '%t' => "\t",
        '%T' => '%H:%M:%S',
        '%u' => ($w = date("w", $ts)) ? $w : 7
    );
    $format = str_replace(
        array_keys($mapping),
        array_values($mapping),
        $format
    );

    return strftime($format, $ts);
}

?>

neo at gothic-chat d0t de (25-Jun-2004 07:27)

To get a RFC 850 date (used in HTTP) of the current time:

gmstrftime ("%A %d-%b-%y %T %Z", time ());

This will get for example:
Friday 25-Jun-04 03:30:23 GMT

Please note that times in HTTP-headers _must_ be GMT, so use gmstrftime() instead of strftime().

vminarik at ips-ag dot cz (10-Sep-2001 02:02)

Note that setting LC_TIME is not enough for some locales under Windows, e.g. Czech, because there are some characters not contained in default (US) character set like '?' (c with hook), '?' (r with hook).


If you run Apache as regular application and have set your locale to Czech (ControlPanel/RegionalOptions), there is no problem and 'September' is correctly translated as 'z???', 'Thursday' as '?tvrtek'.
But if you run Apache as service, you get 'z?r?', and 'ctvrtek'.
To get things work as you expect you must set LC_CTYPE beside LC_TIME, or set LC_ALL.

<?php
  $locale = 'Czech_Czech.1250';
  $res = setlocale( 'LC_CTYPE', $locale); //important
  $res = setlocale( 'LC_TIME', $locale);
  echo strftime( '%A %m. %B %Y', mktime( 0,0,0,9,6,2001));
?>

zmajeed at cup dot hp dot com (22-Jul-1999 11:14)

Locale names are OS dependent. HP-UX 11.0, for example, has three
German locales, de_DE.roman8, de_DE.iso88591, and
de_DE.iso885915@euro.
The command locale -a will display all available locales on a system.

So on HP-UX, to get German dates:

<?php
setlocale("LC_TIME", "de_DE.roman8");
print(strftime("%A\n"));
?>