Time Zone Calculator is a freeware program, that knows everything about world time zones (including utc time zone of course). It can easily convert one time zone to another. For example UTC / GMT time zone to USA zones: Central (CST) or Mountain (MST), Pacific (PST) or Eastern (EST), Atlantic (AST) or Hawaiian (HST). Of course Time Zone Calculator can convert any other world time zones (Central to GMT or Pacific to GMT, GST to Singapore time or CET to EST, anything at your service). Time Zone Calculator takes into account Daylight Saving Time (DST) and shows you the current time in the chosen cities and can calculate difference time between them. Professionals who need to monitor processes in different time zones will find that it is really easy-to-use time zone converter.