Once set correctly, it will not need adjustment until the year 2100 (a century year not divisible by 400, which most mechanical calendars are not programmed for). It is a machine that holds a fragment of infinity within its gears.
The ultimate tool watch complication, the chronograph is a stopwatch integrated into a wristwatch. It measures elapsed time with pushers that start, stop, and reset hands. From the iconic tachymeter bezels of racing watches like the Rolex Daytona to the flyback and rattrapante (split-seconds) functions found in aviation and naval chronographs, it represents man's desire to master and measure intervals of his reality.
