Timezone converstion

Hello, I was trying to evaluate tz libs for timezone usage for my application. My need: Given a region id [ex. "America/New_York"] and a UTC time, i want to get the offset i need to get the time for that region. I also need the Day light savings to be accounted. Can I use the libtz library to do this. Please let me if there are any location where I can get some sample code in C/C++ to do this. I tried to get the old archive so that I can find an answer, but its erroring out. Thanks in advance, Rajesh