​x
 
<!DOCTYPE html>
<html>
<body>
​
<?php
$winter=date_create("2016-10-15",timezone_open("America/New_York"));
$summer=date_create("2016-01-28",timezone_open("America/New_York"));
​
echo date_offset_get($winter) . " 秒。<br />";
echo date_offset_get($summer) . " 秒。";
?>
​
</body>
</html>
​