Datograph Perpetual - A Lange & Sohne
PRECISION IN THE LONG AND SHORT RUN
The DATOGRAPH PERPETUAL is the first wristwatch for which Lange combined a chronograph with a perpetual calendar. Showing the date, day of week, month, and leap year, this perpetual calendar is engineered to such accuracy that it requires no adjustment until the year 2100, when a one-day correction is needed. The chronograph function allows short-time measurements with an accuracy of one-fifth of a second.