Converting DateTime String to Different Timezones in PHP

Question

ok i have this following codes

$from = "Asia/Manila";
$to = "UTC";
$org_time = new DateTime("2012-05-15 10:50:00");
$org_time = $org_time->format("Y-m-d H:i:s");
$conv_time = NULL;

$userTimezone = new DateTimeZone($from);
$gmtTimezone = new DateTimeZone($to);
$myDateTime = new DateTime($org_time, $gmtTimezone);
$offset = $userTimezone->getOffset($myDateTime);
$conv_time = date('Y-m-d H:i:s', $myDateTime->format('U') + $offset);
echo $conv_time;

with this code i want to convert 2012-05-15 10:50:00 to UTC and -8 Timezone(I used America/Vancouver) but it gives me a strange results

Asia/Manila > UTC  
2012-05-15 19:50:00 = the correct is 2012-05-15 02:50

and for America/Vancouver

Asia/Manila > America/Vancouver 
2012-05-16 02:50:00 = the correct is 2012-05-14 19:50

where I went wrong?

Answer 1

You are making things way too hard. To convert between time zones, all you need to do is create a DateTime object with the proper source time zone, and then set the destination time zone via setTimeZone().

$src_dt = '2012-05-15 10:50:00';
$src_tz =  new DateTimeZone('Asia/Manila');
$dest_tz = new DateTimeZone('America/Vancouver');

$dt = new DateTime($src_dt, $src_tz);
$dt->setTimeZone($dest_tz);

$dest_dt = $dt->format('Y-m-d H:i:s');