use strtotime() and then the relative times for them.
For example, to find the US time from my server, its -5 hours, soooo...
strtotime('now -5 hours');
That would return the timestamp for now minus 5 hours (really? how unpredictable!) which is the time for the US (well, some of it, it's a big place you know)
Then you just need to format it like so...
date('G:i D jS M \'y',strtotime('now -5 hours'));
Returns:
20:47 Sat 19th Nov '05