Time Zone Master internally uses the comprehensive Olson Zoneinfo tz database, maintained using input from hundreds of corporate contributors worldwide. Whenever any regional clock law change become known and confirmed, the database is quickly updated. Time Zone Master then automatically downloads and installs these updates within hours, not months. With Time Zone Master, your displayed clocks will always be as accurate as possible now. Time Zone Master adds over 200 countries, over 45,000 towns, and cities to its database, making it easy to select your clocks. Time Zone Master is also a astronomical clock, showing Sunrise/Sunset, Moonrise/Moonset, the times of moon phases, and the start of the seasons, the local Mean Time, Equation of time, Solar Sundial Time, Sidereal Time, and Terrestrial Time for each.