A Lange Sohne 2025 Perpetual Calendar Date. Its integration into the prominent dial layout of the lange 1 was made possible thanks to a peripheral month ring created. Its key element is a patented peripheral month ring, which constituted.

The new lange 1 perpetual calendar is totally focused on the eponymous complication. The only thing that an annual calendar can’t do (which a perpetual calendar can) is to take into account the month of february and its 28 days (or 29 for leap years).