Help Converting Dates

[socals]

I'm trying to convert different date/time strings from different GMT settings into the same format as the vBulletin TIMENOW, so that I can store them in a dateline field.

Example of my date/time strings:

2004-09-18T17:57:00+00:00
2004-09-13T06:44:30-07:00
Wed, 15 Sep 2004 08:15:00 PST

Any help would be greatly appreciated.

I'm taking RSS feeds and storing them in a database, and I'd like to use the same vBulletin date format.

What I have so far is a manual way for the 1st 2 dates in my list:

$newsdate = $this->dcdate;
//$newsdate = "2004-09-18T12:28:30-07:00";
$nyear = substr($newsdate,0,4);
$nmonth = substr($newsdate,5,2);
$nday = substr($newsdate,8,2);
$nhour = substr($newsdate,11,2);
$nmin = substr($newsdate,14,2);
$nsec = substr($newsdate,17,2);
$dateline = mktime($nhour, $nmin, $nsec, $nmonth  , $nday, $nyear);

I would still need to write code to manually fix the GMT time, but I figure there is a routine to do this? Or an easier way than my attempt?