A. Lange & Söhne Richard Lange Terraluna perpetual calendar

A. Lange & Söhne introduced the Richard Lange Ewiger Kalender Terraluna at SIHH 2014.

The dial

The watch has the “régulateur” style dial of the Richard Lange family. The typical Lange date window is at 12 o’clock, the leap year indication at 2 o’clock, the day is shown in the seconds display and the month in the hours display. All the indications switch precisely. The 14-day power reserve is shown at 6 o’clock. The case measures 45.5 mm and comes in rose or white gold.

White gold Richard Lange perpetual calendar with big date window, silver dial and black alligator strap — Richard Lange Ewiger Kalender Terraluna in white gold

Close-up of silver dial with PERPETUAL CALENDAR lettering, red numerals, OCT month window and blued hands — The perpetual calendar dial

The terraluna display

Turn the watch over and the sapphire crystal case back shows the terraluna display and, on closer inspection, the 10-second remontoir.

Rose gold caseback with blue Terraluna disc showing the earth and moon, engraved serial number on the case — The terraluna display seen through the case back

Close-up of the Terraluna movement with blue sapphire disc, gold wheels, blued screws and engraved bridges — Movement detail with the remontoir

The terraluna display shows the earth as seen from the North Pole, a 24-hour scale and the moon phase, calculated at 29 days, 12 hours, 44 minutes and 9.6 seconds. This gives a moon phase error of one day in 1,058 years. The balance indicates the sun.

Terraluna movement with blue sapphire disc and gold train seen from above on a dark background — The movement from above

Technical diagram on light background of the Terraluna display with earth, moon, sun and 24 hour scale labels — Diagram of the terraluna display: earth, moon, sun and 24-hour scale

A. Lange & Söhne Richard Lange Ewiger Kalender Terraluna

The dial

The terraluna display