PHP: strftime - Manual

Description

strftime(string $format, ?int $timestamp = null): string|false

Format the time and/or date according to locale settings. Month and weekday names and other language-dependent strings respect the current locale set with setlocale().

Warning

Not all conversion specifiers may be supported by your C library, in which case they will not be supported by PHP's strftime(). Additionally, not all platforms support negative timestamps, so your date range may be limited to no earlier than the Unix epoch. This means that %e, %T, %R and, %D (and possibly others) - as well as dates prior to Jan 1, 1970 - will not work on Windows, some Linux distributions, and a few other operating systems. For Windows systems, a complete overview of supported conversion specifiers can be found at » MSDN. Instead use the IntlDateFormatter::format() method.

Parameters

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) through `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`
`%k`	Hour in 24-hour format, with a space preceding single digits	`0` 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 preceding 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. The exact result depends on the Operating System, and they can also return lower-case variants, or variants with dots (such as `a.m.`).
`%P`	lower-case 'am' or 'pm' based on the given time	Example: `am` for 00:31, `pm` for 22:23. Not supported by all Operating Systems.
`%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`	The time zone offset. Not implemented as described on Windows. See below for more information.	Example: `-0500` for US Eastern Time
`%Z`	The time zone abbreviation. Not implemented as described on Windows. See below for more information.	Example: `EST` for Eastern Time
Time and Date Stamps	---	---
`%c`	Preferred date and time stamp based on locale	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 ("%")	---

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.

The %z and %Z modifiers both return the time zone name instead of the offset or abbreviation.

Warning

macOS and musl only: The %P modifier is not supported in the macOS implementation of this function.

timestamp

The optional timestamp parameter is an int Unix timestamp that defaults to the current local time if timestamp is omitted or null. In other words, it defaults to the value of time().

Return Values

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(). The function returns false if format is empty, contains unsupported conversion specifiers, or if the length of the returned string would be greater than 4095.

Errors/Exceptions

Every call to a date/time function will generate a E_WARNING if the time zone is not valid. See also 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.

Changelog

Version	Description
8.0.0	`timestamp` is nullable now.

Examples

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

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";
}
?>

The above example will output something similar to:

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'                       ( Hour in 24-hour format, with a space preceding single digits )
Unknown format : 'l'                       ( Hour in 12-hour format, with a space preceding 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'

Notes

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.

strftime

Description

Parameters

Return Values

Errors/Exceptions

Changelog

Examples

Notes

See Also

User Contributed Notes 1 note