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.

The calibre L952.1 movement consists of 556 parts – the calendar mechanism alone incorporates 223 components. The chronograph mechanism is controlled by a classic column wheel that coordinates all switching sequences. Rockers and levers of various shapes engage with this wheel. The considerable length of the levers is due to the special dial arrangement. They bypass the outsize date mechanism and bridge the distance to the subsidiary dials located below the centre line.
 

Technical Details

Winding mechanism – Manually wound movement

Power reserve – 36 hours

Water resistance- 3 bar

Complications – Outsize date, calendar function, moon-phase display, chronograph, Day/night indicator

Case material – 18-carat white gold, Case back: sapphire glass

Case dimension – Case diameter: 41 mm, Case thickness: 13.5 mm

Dial colour – Grey/rhodié

Metal weight – 143 gr

Strap – Black, Alligator leather

Buckle – 18-carat white gold

Distance between horns – 20 mm

Movement designation – L952.1

Number of movement parts – 556