定义和用法

strftime() 函数根据区域设置格式化本地时间／日期。

语法

strftime(format,timestamp)参数 描述
format 可选。规定如何返回结果。
timestamp 可选。
提示和注释
提示：与 gmstrftime() 的行为相同，不同的是返回时间是本地时间。

例子

输出 strftime() 和 gmstrftime() 的结果：

<?php教程
echo(strftime("%b %d %Y %X", mktime(20,0,0,12,31,98)));
echo(gmstrftime("%b %d %Y %X", mktime(20,0,0,12,31,98)));

//

strftime()函数可以把YYYY-MM-DD HH:MM:SS格式的日期字符串转换成其它形式的字符串。
strftime()的语法是strftime(格式, 日期/时间, 修正符, 修正符, ...)

它可以用以下的符号对日期和时间进行格式化：

这个参数的最大长度是 1023 个字符。

Warning
尽管 ISO 98:1999（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。所以 %u 的结果也许不会和手册里描述得一样。

Warning
仅针对 Windows：这个函数里 %e 修饰符修饰符还不能支持 Windows。 为了得到这个值可以用 %#d 修饰符来代替。下例说明了如何写一个跨平台支持的函数。

Warning
仅针对 Mac OS X：这个函数里 %P 修饰符还不能支持 Mac OS X。

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。

strftime()的用法举例如下：

select strftime('%Y.%m.%d %H:%M:%S','now','localtime');
结果：2018.06.21 21:41:09
其实更好的用法是这样的,比如统,本月或本年的支出:
select strftime('%Y-%m',日期) as 月份,sum(支出) as 月支出 from 流水帐 group by 月份;

Example #1 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 #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";

?>

Example #3 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#', '\1%#d', $format);
}

echo strftime($format);
?>

Example #4 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' => 'Hour in 24-hour format, with a space preceding single digits',
 'l' => 'Hour in 12-hour format, with a space preceding 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";
}
?>

下面是其他网友的补充

php strftime()的使用

string strftime ( string format[,inttimestamp = time() ] )

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。

Example1:

<?php
echo '本年中的第·' . strftime('%W', strtotime('+2 week midnight -0 second')) . '·周';
?>

本年中的第·31·周

Example2:

<?php
echo "現在時間是：" . strftime('%d.%B %Y %H:%M:%S', time());
?>

現在時間是：20.July 2015 17:01:26

Example3:

<?php
echo '日期時間格式化為:' . strftime('%d.%B %Y %H:%M:%S', strtotime('2018-10-15'));
?>

日期時間格式化為:15.October 2018 00:00:00