April 2000 Timepieces/Data & Statistics Watch Time Change A CD from IWC details how a perpetual calendar works Watch connoisseurs can now explore what’s normally reserved for watchmakers: the full internal workings of the IWC Da Vinci perpetual calendar. On a new CD-ROM from IWC, the hundreds of parts and groups of components that make up the Da Vinci’s perpetual calendar are shown and precisely explained. Using sophisticated animation, the CD-ROM provides the viewer with a detailed explanation of the workings of the perpetual calendar through the year 2499. As the timepiece changes years, leap years, days, weeks or moonphases, the viewer can watch the intricate movement step-by-step or as a “movie.” Commentary in English, French, German, Italian and Spanish explains the complex sequences in simple terms. The CD-ROM has a fully functional on-screen Da Vinci that is synchronized to the computer’s built-in clock. All watch functions can be activated by mouse click. The CD can be ordered from IWC for $21. Contact International Watch Co., Winchester, VA; (800) 432-9330 or check out its Web site (www.iwc.ch) for more details. – by Michael Thompson Inside and outside views of the Da Vinci perpetual calendar from International Watch Co.