PHP Timestamp into DateTime

Question

Do you know how I can convert this to a strtotime, or a similar type of value to pass into the DateTime object?

The date I have:

Mon, 12 Dec 2011 21:17:52 +0000

What I've tried:

$time = substr($item->pubDate, -14);
$date = substr($item->pubDate, 0, strlen($time));

$dtm = new DateTime(strtotime($time));
$dtm->setTimezone(new DateTimeZone(ADMIN_TIMEZONE));
$date = $dtm->format('D, M dS');
$time = $dtm->format('g:i a');

The above is not correct. If I loop through a lot of different dates its all the same date.

Aldon

Answer 1

You don't need to turn the string into a timestamp in order to create the DateTime object (in fact, its constructor doesn't even allow you to do this, as you can tell). You can simply feed your date string into the DateTime constructor as-is:

// Assuming $item->pubDate is "Mon, 12 Dec 2011 21:17:52 +0000"
$dt = new DateTime($item->pubDate);

That being said, if you do have a timestamp that you wish to use instead of a string, you can do so using DateTime::setTimestamp():

$timestamp = strtotime('Mon, 12 Dec 2011 21:17:52 +0000');
$dt = new DateTime();
$dt->setTimestamp($timestamp);

Edit (2014-05-07):

I actually wasn't aware of this at the time, but the DateTime constructor does support creating instances directly from timestamps. According to this documentation, all you need to do is prepend the timestamp with an @ character:

$timestamp = strtotime('Mon, 12 Dec 2011 21:17:52 +0000');
$dt = new DateTime('@' . $timestamp);

Panpsychist

This works great. I had tried this previously but must have not given it enough of a chance!!! thanks :)) – Aldon

Note that new DateTime('@' . $timestamp) and $dt = new DateTime(); $dt->setTimestamp($timestamp) don't deal with timezones the same way. See my answer @ #12039058 for more details. – Brenza

I think new DateTime("@$timestamp") may be more readable. – Proselyte

A little shorter: $date = (new DateTime)->setTimestamp($timestamp); – Crispen

Answer 2

While @drrcknlsn is correct to assert there are multiple ways to convert a time string to a datatime, it's important to realize that these different ways don't deal with timezones in the same way.

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Option 1 : DateTime('@' . $timestamp)

Consider the following code :

date_format(date_create('@'. strtotime('Mon, 12 Dec 2011 21:17:52 +0800')), 'c');

The strtotime bit eliminates the time zone information, and the date_create function assumes GMT.

As such, the output will be the following, no matter which server I run it on :

2011-12-12T13:17:52+00:00

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Option 2 : date_create()->setTimestamp($timestamp)

Consider the following code :

date_format(date_create()->setTimestamp(strtotime('Mon, 12 Dec 2011 21:17:52 +0800')), 'c');

You might expect this to produce the same output. However, if I execute this code from a Belgian server, I get the following output :

2011-12-12T14:17:52+01:00

Unlike the date_create function, the setTimestamp method assumes the time zone of the server (CET in my case) rather than GMT.

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Explicitly setting your time zone

If you want to make sure your output matches the time zone of your input, it's best to set it explicitly.

Consider the following code :

date_format(date_create('@'. strtotime('Mon, 12 Dec 2011 21:17:52 +0800'))->setTimezone(new DateTimeZone('Asia/Hong_Kong')), 'c')

Now, also consider the following code :

date_format(date_create()->setTimestamp(strtotime('Mon, 12 Dec 2011 21:17:52 +0800'))->setTimezone(new DateTimeZone('Asia/Hong_Kong')), 'c')

Because we explicitly set the time zone of the output to match that of the input, both will create the same (correct) output :

2011-12-12T21:17:52+08:00

Brenza

Answer 3

Probably the simplest solution is just:

DateTime::createFromFormat('U', $timeStamp);

Where 'U' means Unix epoch. See docs: http://php.net/manual/en/datetime.createfromformat.php

Gina

This method also ignores timezone – Stepup

@BoukeVersteegh and which one doesn't? – Gina

@BoukeVersteegh This is a Unix timestamp!, it frees you from timezones problems while creating the object. just use ->setTimezone to set the preferable timezone before calling ->format() – Waylan

@BoukeVersteegh Check this big note from the PHP 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). " – Waylan

Unix timestamps don't have timezones, they are always UTC by definition – Tarnation

Answer 4

This is my solution:

function changeDateTimezone($date, $from='UTC', $to='Asia/Tehran', $targetFormat="Y-m-d H:i:s") {
    $date = new DateTime($date, new DateTimeZone($from));
    $date->setTimeZone(new DateTimeZone($to));
    return $date->format($targetFormat);
}

Yacano