PHP timezone modification script

I have downloaded a script that calculates timezone / date under the GPL. Currrently, it takes the current time and converts it into time/date in the selected timezone. I want the function modified so i can pass in a time to be converted, rather than the current system time. Basically, I want to pass in a GMT time when I call the function, and have it return the converted time for the time zone selected. So if i pass in 1/24/06 13:50, it is assumed that is the time in GMT, and the function should return converted time in whatever time zone I have selected. Eventually, the time will come from a datasource like MySQL. For now, it can be hardcoded for testing purposes in the function call (something like gettime('1/24/06 13:50',$timezone)). You are also free to create a whole new function if you prefer, as long as it converts the GMT time passed into the function into the time/date of the timezone selected. It must also automatically adjust for Daylight Savings time. here is where the script lies: [login to view URL]