(PHP 4, PHP 5, PHP 7, PHP 8)
strtotime — Parse about any English textual datetime description into a Unix timestamp
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.
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.
datetimeA date/time string. Valid formats are explained in Date and Time Formats.
baseTimestampThe timestamp which is used as a base for the calculation of relative dates.
Returns a timestamp on success, false otherwise.
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()
| Version | Description |
|---|---|
| 8.0.0 |
baseTimestamp is nullable now.
|
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);
}
?>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 as31 February 2022, which will overflow into a timestamp on3 March. (In a leap year, it would be2 March.) Usingstrtotime('1 February')orstrtotime('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().
Be careful when using two numbers as the year. I came across this situation:
<?php
echo strtotime('24.11.22');
echo date('d.m.Y H:i:s', 1669324282) . "\n\n";
// But
echo strtotime('24.11.2022');
echo date('d.m.Y H:i:s', 1669237200);
?>
Output:
1669324282
25.11.2022 00:11:22
1669237200
24.11.2022 00:00:00Not sure why, but
<?php
echo strtotime("+2 hours"), "\n";
echo strtotime("+2 hrs"), "\n";
echo strtotime("+2 hourss"), "\n";
?>
are returning +2 hours, -2 hours, +8 hours. The latter two should be errors instead.Be aware of this: 1 month before the 31st day, it will return the same month:
<?php
echo date('m', strtotime('2023-05-30 -1 month')) ; //returns 04
echo date('m', strtotime('2023-05-31 -1 month')) ; //returns 05, not 04
?>
So, don't use this to operate on the month of the result.
A better way to know what month was the previous month would be:
<?php
//considering today is 2023-05-31...
$firstOfThisMonth = date('Y-m') . '-01'; //returns 2023-05-01
echo date('m', strtotime($firstOfThisMonth . ' -1 month')) ; //returns 04
?>> 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.
important - does not contain
<?php
date_default_timezone_set('Europe/Berlin');
// .... a lot of code
echo $a = strtotime('yesterday 00:00');
// in $a hour = 23:00:00 and you may not know about it
// https://onlinephp.io/c/ef696
// use DateTimeImmutable