How to convert date to timestamp in PHP?

This method works on both Windows and Unix and is time-zone aware, which is probably what you want if you work with dates.

If you don't care about timezone, or want to use the time zone your server uses:

$d = DateTime::createFromFormat('d-m-Y H:i:s', '22-09-2008 00:00:00');
if ($d === false) {
    die("Incorrect date string");
} else {
    echo $d->getTimestamp();
}

1222093324 _{(This will differ depending on your server time zone...)}

If you want to specify in which time zone, here EST. (Same as New York.)

$d = DateTime::createFromFormat(
    'd-m-Y H:i:s',
    '22-09-2008 00:00:00',
    new DateTimeZone('EST')
);

if ($d === false) {
    die("Incorrect date string");
} else {
    echo $d->getTimestamp();
}

1222093305

Or if you want to use UTC. (Same as "GMT".)

$d = DateTime::createFromFormat(
    'd-m-Y H:i:s',
    '22-09-2008 00:00:00',
    new DateTimeZone('UTC')
);

if ($d === false) {
    die("Incorrect date string");
} else {
    echo $d->getTimestamp();
}

1222093289

Regardless, it's always a good starting point to be strict when parsing strings into structured data. It can save awkward debugging in the future. Therefore I recommend to always specify date format.

There is also strptime() which expects exactly one format:

$a = strptime('22-09-2008', '%d-%m-%Y');
$timestamp = mktime(0, 0, 0, $a['tm_mon']+1, $a['tm_mday'], $a['tm_year']+1900);

Be careful with functions like strtotime() that try to "guess" what you mean (it doesn't guess of course, the rules are here).

Indeed 22-09-2008 will be parsed as 22 September 2008, as it is the only reasonable thing.

How will 08-09-2008 be parsed? Probably 09 August 2008.

What about 2008-09-50? Some versions of PHP parse this as 20 October 2008.

So, if you are sure your input is in DD-MM-YYYY format, it's better to use the solution offered by @Armin Ronacher.

Using mktime:

list($day, $month, $year) = explode('-', '22-09-2008');
echo mktime(0, 0, 0, $month, $day, $year);

Use PHP function strtotime()

echo strtotime('2019/06/06');

date — Format a local time/date

If you know the format use strptime because strtotime does a guess for the format, which might not always be correct. Since strptime is not implemented in Windows there is a custom function

• http://nl3.php.net/manual/en/function.strptime.php#86572

Remember that the returnvalue tm_year is from 1900! and tm_month is 0-11

Example:

$a = strptime('22-09-2008', '%d-%m-%Y');
$timestamp = mktime(0, 0, 0, $a['tm_mon']+1, $a['tm_mday'], $a['tm_year']+1900)

<?php echo date('M j Y g:i A', strtotime('2013-11-15 13:01:02')); ?>

http://php.net/manual/en/function.date.php

For PHP >=5.3, 7 & 8 the this may work-

$date = date_parse_from_format('%Y-%m-%d', "2022-11-15"); //here you can give your desired date in desired format. 
                                                           //just need to keep in mind that date and format matches.

$timestamp = mktime(0, 0, 0, $date['month'], $date['day'], $date['year'] + 2000); //this will return the timestamp

$finalDate= date('Y-m-d H:i:s', $timestamp); //now you can convert your timestamp to desired dateTime format.

If you already have the date in that format, you only need to call the "strtotime" function in PHP.

$date = '22-09-2008';
$timestamp = strtotime($date);
echo $timestamp; // 1222041600

Or in a single line:

echo strtotime('22-09-2008');

Short and simple.