使用strtotime与TimeZone

Question

I have a problem. I want to convert this DateTime: 2018-10-28 02:00:00 to a TimeStamp. Now the TimeStamp I am looking for is: 1540684800, but with my code I get this TimeStamp: 1540688400. I know it has something to do with my TimeZone, but I don't know how I can fix this. I live in the Netherlands in Amsterdam. Here is my code:

$LoopDateTime = "2018-10-28 02:00:00";
$search_key = (strtotime($LoopDateTime)*1000);

Can someone help me?

Answer 1

The time zone identifier for Amsterdam is Europe/Amsterdam and 1540688400 is the correct timestamp. There's surely an online tool to check but you can also verify it from PHP itself:

$date = new DateTime("@1540688400");
$date->setDateTimeZone(new DateTimeZone('Europe/Amsterdam'));
echo $date->format('r'); // Sun, 28 Oct 2018 02:00:00 +0100

However your code is not robust because depends on the configured timezone. You can just set it explicitly in a number of ways, e.g.:

$LoopDateTime = "2018-10-28 02:00:00";
$search_key = strtotime($LoopDateTime . ' Europe/Amsterdam') * 1000;
var_dump($search_key); // int(1540688400000)

Or:

date_default_timezone_set('Europe/Amsterdam');
$LoopDateTime = "2018-10-28 02:00:00";
$search_key = strtotime($LoopDateTime) * 1000;
var_dump($search_key); // int(1540688400000)

P.S. If I'm not wrong Sunday 28 Oct 2018 02:00:00 +0100 is the exact moment when most Europe has just switched from CEST (+0200) to CET (+0100).