How to convert date to timestamp in PHP?

Question

How do I get timestamp from e.g. 22-09-2008?

Answer 1

Please be careful about time/zone if you set it to save dates in database, as I got an issue when I compared dates from mysql that converted to timestamp using strtotime. you must use exactly same time/zone before converting date to timestamp otherwise, strtotime() will use default server timezone.

Please see this example: https://3v4l.org/BRlmV

function getthistime($type, $modify = null) {
    $now = new DateTime(null, new DateTimeZone('Asia/Baghdad'));
    if($modify) {
        $now->modify($modify);
    }
    if(!isset($type) || $type == 'datetime') {
        return $now->format('Y-m-d H:i:s');
    }
    if($type == 'time') {
        return $now->format('H:i:s');
    }
    if($type == 'timestamp') {
        return $now->getTimestamp();
    }
}
function timestampfromdate($date) {
    return DateTime::createFromFormat('Y-m-d H:i:s', $date, new DateTimeZone('Asia/Baghdad'))->getTimestamp();
}

echo getthistime('timestamp')."--".
    timestampfromdate(getthistime('datetime'))."--".
    strtotime(getthistime('datetime'));

//getthistime('timestamp') == timestampfromdate(getthistime('datetime')) (true)
//getthistime('timestamp') == strtotime(getthistime('datetime')) (false)

Answer 2

Use PHP function date()

echo date('m/d/Y', 1299446702);

date — Format a local time/date

Answer 3

Here is how I'd do it:

function dateToTimestamp($date, $format, $timezone='Europe/Belgrade')
{
    //returns an array containing day start and day end timestamps
    $old_timezone=date_timezone_get();
    date_default_timezone_set($timezone);
    $date=strptime($date,$format);
    $day_start=mktime(0,0,0,++$date['tm_mon'],++$date['tm_mday'],($date['tm_year']+1900));
    $day_end=$day_start+(60*60*24);
    date_default_timezone_set($old_timezone);
    return array('day_start'=>$day_start, 'day_end'=>$day_end);
}

$timestamps=dateToTimestamp('15.02.1991.', '%d.%m.%Y.', 'Europe/London');
$day_start=$timestamps['day_start'];

This way, you let the function know what date format you are using and even specify the timezone.

Answer 4

If you have PHP 5.3 or above,

this method works on both Windows and Unix and is time-zone aware, which is probably what you want if you are serious about working 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', '22-09-2008');
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', '22-09-2008', new DateTimeZone('EST'));
echo $d->getTimestamp();

1222093305

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

$d = DateTime::createFromFormat('d-m-Y', '22-09-2008', new DateTimeZone('UTC'));
echo $d->getTimestamp();

1222093289

Answer 5

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)

Answer 6

Given that the function strptime() does not work for Windows and strtotime() can return unexpected results, I recommend using date_parse_from_format():

$date = date_parse_from_format('d-m-Y', '22-09-2008');
$timestamp = mktime(0, 0, 0, $date['month'], $date['day'], $date['year']);