handling timezone information on Linux/glibc

I have been banging my head on timezone/UTC-offset implementation for my project. Does anyone know of an intelligent GPL-compatibly licensed implementation of a date-time class with time-zone and DST awareness?

Apparently glibc uses the Olson timezone database internally but it does not expose the API to the client programmer (this information from man:tzfile). So would it be helpful if I dig into glibc internals?

Shriramana Sharma.