strtotime

(PHP 4, PHP 5, PHP 7, PHP 8)

strtotime — Parse about any English textual datetime description into a Unix timestamp

Description

strtotime(string $datetime, ?int $baseTimestamp = null): int|false

The function expects to be given a string containing an English date format and will try to parse that format into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 UTC), relative to the timestamp given in baseTimestamp, or the current time if baseTimestamp is not supplied. The date string parsing is defined in Date and Time Formats, and has several subtle considerations. Reviewing the full details there is strongly recommended.

Warning

The Unix timestamp that this function returns does not contain information about time zones. In order to do calculations with date/time information, you should use the more capable DateTimeImmutable.

Each parameter of this function uses the default time zone unless a time zone is specified in that parameter. Be careful not to use different time zones in each parameter unless that is intended. See date_default_timezone_get() on the various ways to define the default time zone.

Parameters

datetime: A date/time string. Valid formats are explained in Date and Time Formats.
baseTimestamp: The timestamp which is used as a base for the calculation of relative dates.

Return Values

Returns a timestamp on success, false otherwise.

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()

Changelog

Version	Description
8.0.0	`baseTimestamp` is nullable now.

Examples

Example #1 A strtotime() example


<?php
echo strtotime("now"), "\n";
echo strtotime("10 September 2000"), "\n";
echo strtotime("+1 day"), "\n";
echo strtotime("+1 week"), "\n";
echo strtotime("+1 week 2 days 4 hours 2 seconds"), "\n";
echo strtotime("next Thursday"), "\n";
echo strtotime("last Monday"), "\n";
?>

Example #2 Checking for failure


<?php
$str = 'Not Good';

if (($timestamp = strtotime($str)) === false) {
    echo "The string ($str) is bogus";
} else {
    echo "$str == " . date('l dS \o\f F Y h:i:s A', $timestamp);
}
?>

Notes

Note:
"Relative" date in this case also means that if a particular component of the date/time stamp is not provided, it will be taken verbatim from the baseTimestamp. That is, strtotime('February'), if run on the 31st of May 2022, will be interpreted as 31 February 2022, which will overflow into a timestamp on 3 March. (In a leap year, it would be 2 March.) Using strtotime('1 February') or strtotime('first day of February') would avoid that problem.

Note:
If the number of the year is specified in a two digit format, the values between 00-69 are mapped to 2000-2069 and 70-99 to 1970-1999. See the notes below for possible differences on 32bit systems (possible dates might end on 2038-01-19 03:14:07).

Note:
The valid range of a timestamp is typically from Fri, 13 Dec 1901 20:45:54 UTC to Tue, 19 Jan 2038 03:14:07 UTC. (These are the dates that correspond to the minimum and maximum values for a 32-bit signed integer.)

For 64-bit versions of PHP, the valid range of a timestamp is effectively infinite, as 64 bits can represent approximately 293 billion years in either direction.

Note:
Using this function for mathematical operations is not advisable. It is better to use DateTime::add() and DateTime::sub().

User Contributed Notes 19 notes

down

122

kumar AT swatantra.info Swatantra Kumar ¶

9 years ago


The "+1 month" issue with strtotime
===================================
As noted in several blogs, strtotime() solves the "+1 month" ("next month") issue on days that do not exist in the subsequent month differently than other implementations like for example MySQL.

<?php
echo date( "Y-m-d", strtotime( "2009-01-31 +1 month" ) ); // PHP:  2009-03-03
echo date( "Y-m-d", strtotime( "2009-01-31 +2 month" ) ); // PHP:  2009-03-31
?>

<?php
SELECT DATE_ADD( '2009-01-31', INTERVAL 1 MONTH ); // MySQL:  2009-02-28
?>

down

cristinawithout ¶

10 years ago


WARNING when using "next month", "last month", "+1 month",  "-1 month" or any combination of +/-X months. It will give non-intuitive results on Jan 30th and 31st. 

As described at : http://derickrethans.nl/obtaining-the-next-month-in-php.html

<?php
$d = new DateTime( '2010-01-31' );
$d->modify( 'next month' );
echo $d->format( 'F' ), "\n";
?>

In the above, using "next month" on January 31 will output "March" even though you might want it to output "February". ("+1 month" will give the same result. "last month", "-1 month" are similarly affected, but the results would be seen at beginning of March.)

The way to get what people would generally be looking for when they say "next month" even on Jan 30 and Jan 31 is to use "first day of next month":

<?php
$d = new DateTime( '2010-01-08' );
$d->modify( 'first day of next month' );
echo $d->format( 'F' ), "\n";
?>

<?php
$d = new DateTime( '2010-01-08' );
$d->modify( 'first day of +1 month' );
echo $d->format( 'F' ), "\n";
?>

down

joe at strtotime dot co dot uk ¶

7 years ago


A useful testing tool for strtotime() and unix timestamp conversion:
http://strtotime.co.uk/

down

michal dot kocarek at brainbox dot cz ¶

13 years ago


strtotime() also returns time by year and weeknumber. (I use PHP 5.2.8, PHP 4 does not support it.) Queries can be in two forms:

- "yyyyWww", where yyyy is 4-digit year, W is literal and ww is 2-digit weeknumber. Returns timestamp for first day of week (for me Monday)

- "yyyy-Www-d", where yyyy is 4-digit year, W is literal, ww is 2-digit weeknumber and dd is day of week (1 for Monday, 7 for Sunday) 



<?php

// Get timestamp of 32nd week in 2009.

strtotime('2009W32'); // returns timestamp for Mon, 03 Aug 2009 00:00:00

// Weeknumbers < 10 must be padded with zero:

strtotime('2009W01'); // returns timestamp for Mon, 29 Dec 2008 00:00:00

// strtotime('2009W1'); // error! returns false



// See timestamp for Tuesday in 5th week of 2008

strtotime('2008-W05-2'); // returns timestamp for Tue, 29 Jan 2008 00:00:00

?>



Weeknumbers are (probably) computed according to ISO-8601 specification, so doing date('W') on given timestamps should return passed weeknumber.

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mirco dot babin at gmail dot com ¶

3 years ago


One important thing you should remember is that the timestamp value returned by time() is time-zone agnostic and gets the number of seconds since 1 January 1970 at 00:00:00 UTC. This means that at a particular point in time, this function will return the same value in the US, Europe, India, Japan, ...

strtotime() will convert a string WITHOUT a timezone indication as if the string is a time in the default timezone ( date_default_timezone_set() ). So converting a UTC time like '2018-12-06T09:04:55' with strtotime() actually yields a wrong result. In this case use:

<?php
function UTCdatestringToTime($utcdatestring)
{
    $tz = date_default_timezone_get();
    date_default_timezone_set('UTC');

    $result = strtotime($utcdatestring);

    date_default_timezone_set($tz);
    return $result;
}
?>

Test:
<?php
$tz = 'Europe/Amsterdam';
$utctime = '2018-12-06T09:04:55';

if (!date_default_timezone_set($tz)) {
    WriteLine('Setting default timezone to ' . $tz . ' failed');
    die;
}

WriteLine();
WriteLine('Default timezone set to ' . $tz);
WriteLine('UTC time: ' . $utctime);
WriteLine();

WriteLine('[ UTCdatestringToTime ]');
$phptime = UTCdatestringToTime($utctime);
WriteLine('PHP time: ' . $phptime);
WriteTime($phptime, true);
WriteTime($phptime, false);
WriteLine();

WriteLine('-------------------------------------------------------------------------------');
WriteLine('[ strtotime($utctime) - Converts $utctime as if it was in timezone ' . $tz . ' because the string has no timezone specification ]');
$phptime = strtotime($utctime); //Seconds since the unix epoch
WriteLine('PHP time: ' . $phptime);
WriteTime($phptime, true);
WriteTime($phptime, false);

function WriteLine($text = '') 
{
    echo $text . "\r\n";
}

function WriteTime($time, bool $asUTC)
{
    $tz = date_default_timezone_get();
    if ($asUTC) date_default_timezone_set('UTC');
    
    WriteLine('--> (' . date_default_timezone_get() . ') ' . date('Y-m-d H:i:s', $time));
    
    if ($asUTC) date_default_timezone_set($tz);
}
?>

Test output:
<?php

Default timezone set to Europe/Amsterdam
UTC time: 2018-12-06T09:04:55

[ UTCdatestringToTime ]
PHP time: 1544087095
--> (UTC) 2018-12-06 09:04:55
--> (Europe/Amsterdam) 2018-12-06 10:04:55

-------------------------------------------------------------------------------
[ strtotime($utctime) - Converts $utctime as if it was in timezone Europe/Amsterdam because the string has no timezone specification ]
PHP time: 1544083495
--> (UTC) 2018-12-06 08:04:55
--> (Europe/Amsterdam) 2018-12-06 09:04:55
*/
?>

down

Steve GS ¶

4 years ago


The difference between 'today' and 'now' is the former strips off the time (setting it to 00:00, ie. midnight just past), and the latter includes the time - assuming UTC unless specified otherwise.

I run a theatre's website.  Obviously, I need to ensure shows that have already happened do not appear on web pages, so I use something on the lines of:

    $listIt = (strtotime($end_date) >= strtotime('today') ? 1 : 0);

where $end_date is the final date in a show series.  So if tonight's show is the last, it will stay on the web page until 00:00 tomorrow.

I don't normally include performance times in the date field because some shows have matinées, others don't - so I use a free-form performance time field in the CMS instead (where even 'Time: TBD' is allowed).  [The only instance where I DO include the time is when there are two different shows on the same day, to ensure they appear in chronological order.]

So strtotime($end_date) will always return the timestamp at 00:00 that day.  If I instead used:

    $listIt = (strtotime($end_date) >= strtotime('now') ? 1 : 0);

the function would return $listIt = 0 at all times today - something I don't want.

HTH

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shannon ¶

4 years ago


I tried using sams most popular example but got incorrect results.

Incorrect:
<?php 
echo date("jS F, Y", strtotime("11.12.10")); 
// outputs 10th December, 2011 

echo date("jS F, Y", strtotime("11/12/10")); 
// outputs 12th November, 2010 

echo date("jS F, Y", strtotime("11-12-10")); 
// outputs 11th December, 2010  
?> 

Then I read the notes which said:
if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed. ***If, however, the year is given in a two digit format and the separator is a dash (-), the date string is parsed as y-m-d.***

Therefore, the above code does not work on 2 digit years - only 4 digit years

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me at will morgan dot co dot you kay ¶

9 years ago


For negative UNIX timestamps, strtotime seems to return the literal you passed in, or it may try to deduct the number of seconds from today's date.

To work around this behaviour, it appears that the same behaviour as described in the DateTime classes applies:

http://php.net/manual/en/datetime.construct.php

Specifically this line here (in the EN manual):

> The $timezone parameter and the current timezone are ignored when the $time parameter either is a UNIX timestamp (e.g. @946684800) or specifies a timezone (e.g. 2010-01-28T15:00:00+02:00).

Therefore strtotime('@-1000') returns 1000 seconds before the epoch.

Hope this helps.

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marlonsouza90 at hotmail dot com ¶

2 years ago


strtotime();

exemplo strtotime(date("Y-m-d") . "+1month");

A strtotime também funciona quando concatenamos strings,

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chris at teamsiems dot com ¶

12 years ago


It took me a while to notice that strtotime starts searching from just after midnight of the first day of the month. So, if the month starts on the day you search for, the first day of the search is actually the next occurrence of the day.



In my case, when I look for first Tuesday of the current month, I need to include a check to see if the month starts on a Tuesday.



<?php

if (date("l", strtotime("$thisMonth $thisYear"))=='Tuesday') {

  echo "<p>This month starts on a Tuesday. Use \"$thisMonth $thisYear\" to check for first Tuesday.</p>\n";

} else {

  echo "<p>This month does not start on a Tuesday. Use \"first tuesday $thisMonth $thisYear\" to check for first Tuesday.</p>\n";

}

?>

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kyle at frozenonline dot com ¶

18 years ago


I was having trouble parsing Apache log files that consisted of a time entry (denoted by %t for Apache configuration). An example Apache-date looks like: [21/Dec/2003:00:52:39 -0500]

Apache claims this to be a 'standard english format' time. strtotime() feels otherwise. 

I came up with this function to assist in parsing this peculiar format.

<?php
function from_apachedate($date)
{
        list($d, $M, $y, $h, $m, $s, $z) = sscanf($date, "[%2d/%3s/%4d:%2d:%2d:%2d %5s]");
        return strtotime("$d $M $y $h:$m:$s $z");
}
?>

Hope it helps anyone else seeking such a conversion.

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Michael Muryn (MickoZ) ¶

10 years ago


[red.: This is a bug, and should be fixed. I have file an issue]



This comment apply to PHP5+



We can now do thing like this with strtotime:

<?php 

$weekMondayTime = strtotime('Monday this week');

?>

However this works based on a week starting Sunday.  I do not know if we can tweak this PHP behavior, anyone know?



If you want the timestamp of the start of the ISO Week (i.e. on Monday) as defined by ISO 8601, you can use this one liner:

<?php

$isoWeekStartTime = strtotime(date('o-\\WW')); // {isoYear}-W{isoWeekNumber}

?>



You can also find out the start of week of any time and format it into an ISO date with another one liner like this:

<?php

$isoWeekStartDate = date('Y-m-d', strtotime(date('o-\\WW', $time)));

?>



For more information about ISO-8601 and ISO week date:

http://en.wikipedia.org/wiki/ISO_8601#Week_dates

http://en.wikipedia.org/wiki/ISO_week_date

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a dot fruchi at bit-runners dot com ¶

11 years ago


If you want to confront a date stored into mysql as a date field (not a datetime) and a date specified by a literal string, be sure to add "midnight" to the literal string, otherwise they won't match:

<?php
//I.E.: today is 17/02/2011

echo strtotime('2011-01-01'); //1293836400
echo strtotime('first day of last month'); //1293888128 Note: it's different from the previous one, since it computes also the seconds passed from midnight!!! So this one is always greater than simple '2011-01-01'
echo strtotime('midnight first day of last monty');//1293836400 Note: it's the same as '2011-01-01'

?>

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Black Hat Rocker ¶

1 year ago


*The case 30/11/-0001* 
With the following note, I will report a particular behaviour of function strtotime() I want to call it «The case 30/11/-0001».  It is very common and known but never reported  here. Passing the input parameter '0000-00-00' to the function it returns a wrong and not supported timestamp value. It can be seen with these statement

<?php echo date('d/m/Y', strtotime('0000-00-00')); // returns 30/11/-0001  ?>

It seems there's no way to avoid that, but it is possibile to do workaround with if/3operator clausole simply as follow

<?php strcmp($date "0000-00-00")? date('d/m/Y', strtotime($date) ) :  date('d/m/Y') ?>

Otherwise a simple way is to avoid to store to the DB the value '0000-00-00' and insert a default data value (i.e. with the mySQL function NOW() which sets the date on today's date)

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-2

phpmanual at NOSPAM dot headbank dot co dot uk ¶

1 month ago


For those still using php versions < 8.0.0, it may help to know that explicitly supplying the 2nd argument $baseTime as NULL does *not* have the same effect as omitting it.

<?php
function adjustedTime($adjustment, $baseTime = null) {
  echo date('Y-m-d H:i:s', strtotime($adjustment, $baseTime));
}

adjustTime('+1 day');

//1970-01-02 01:00:00
?>
Supplying NULL is equivalent to supplying int(0).

So if you wrap strtotime() in this manner with a nullable $baseTime, make sure in your code to inspect $baseTime and supply time() instead of NULL, or call strtotime() without it in that case.

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vlad dot savitsky at gmail dot com ¶

4 years ago


Little bit unexpected behaviour for me. Small integers treats like time.
strtotime(0) => false,
strtotime(1) => false,
strtotime(12) => false,
strtotime(123) => false,
strtotime(1234) => 1528194840, //Time '12:34'
strtotime(12345) => false,
strtotime(123456) => 1528194896, // Time '12:34:56'
strtotime(1234567) => false,
strtotime(12345678) => false,
strtotime(123456789) => false,

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-1

marcodemaio at vanylla dot it ¶

11 years ago


NOTE: strtotime returns different values when the Week day does not match the date.



Simple example:



<?php

$d1 = strtotime("26 Oct 0010 12:00:00 +0100");

$d2 = strtotime("Tue, 26 Oct 0010 12:00:00 +0100");

$d3 = strtotime("Sun, 26 Oct 0010 12:00:00 +0100"); //But Oct 26 is a Tuesday, NOT a Sunday.



echo $d1; //ok 1288090800 that is "26 Ott 2010 - 11:00";

echo $d2; //ok 1288090800 that is "26 Ott 2010 - 11:00";

echo $d3; //WRONG! 1288522800 that is "31 Ott 2010 - 11:00";

?>



Sometime I found RSS feeds that contains week days that do not match the date.



A possible solution is to remove useless week day before passing the date string into strtotime, example:



<?php

   $date_string = "Sun, 26 Oct 0010 12:00:00 +0100";

   if( ($comma_pos = strpos($date_string, ',')) !== FALSE )

      $date_string = substr($date_string, $comma_pos + 1);

   $d3 = strtotime($date_string);

?>

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-2

fuhrysteve at gmail dot com ¶

13 years ago


Here's a hack to make this work for MS SQL's datetime junk, since strtotime() has issues with fractional seconds.

<?php

$MSSQLdatetime = "Feb  7 2009 09:48:06:697PM";
$newDatetime = preg_replace('/:[0-9][0-9][0-9]/','',$MSSQLdatetime);
$time = strtotime($newDatetime);
echo $time."\n";

?>

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-5

Sui Dream ¶

4 years ago


It was really pazzling to me to read about parsing a string into a Unix timestamp relative to both January 1 1970 00:00:00 UTC and the second parameter. Maybe it worth noting that the second parameter is for relative dates (like "+1 day").

＋add a note

strtotime

Description

Parameters

Return Values

Errors/Exceptions

Changelog

Examples

Notes

See Also

User Contributed Notes 19 notes