Question

I have a ISO8601 string with some arbitrary time zone. I don’t want to convert to my time zone. Rather, I want to preserve the original time zone. I want to be able to format the output similar to how gmdate formats the date/time. For example:

$output =  my_date_function( 'F d, ga', $thetime );

Should output:

$thetime = '2012-09-24T21:00:00-0700';
     => September 24, 9pm

$thetime = '2012-09-24T21:00:00-0500';
     => September 24, 9pm

Answer 1

I don’t know if it would work but I think that DateTime::createFromFormat can do it automatically. You can also create a function that determine the timezone and create a DateTimezone object with it.
http://php.net/manual/en/datetime.createfromformat.php
According to the documentation :

If timezone is omitted and time contains no timezone, the current timezone will be used

Code:

$stime = '2012-09-24T21:00:00-0500';
$t = DateTime::createFromFormat(DateTime::ISO8601, substr($stime, 0, 19));
$output = $t->format('F d, ga');