I know I just posted, but I just remembered that I created a very simple GMT time calculator a little while ago. There are plenty out on the net but they all get very complex and never really gave me what I wanted which was to have a destination time, destination gmt, my gmt and work out what time that would mean for me since there I need to calculate this for in game meetings and although it is a simple calculation it never seems it when I am tired, which odly is the time that I am calculating game times.
There is limited validation but your not meant to try to break it only use it.
Here is the link:http://fun.koali.com.au/calculator.php