(PHP 4, PHP 5)
strftime — 根据区域设置格式化本地时间／日期
$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：
尽管 ISO 9889:1999（当前的 C 标准）明确指出一周从星期一开始，但是 Sun Solaris 的一周似乎从星期天开始并作为 1。
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");
?>
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()。
format
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.
Contrary to ISO-9899:1999, Sun Solaris starts with Sunday as 1. As a result, %u may not function as described in this manual.
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.
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。
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().
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.
| 版本 | 说明 |
|---|---|
| 5.1.0 |
现在发布 |
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'
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.