LANGEMATIK PERPETUAL MODEL, REF. 310.021F, MOVEMENT NO. 28’205, CASE NO. 138’275, CIRCA 2004

The Langematik Perpetual was the first mechanical wristwatch to combine a perpetual calendar with a Lange outsize date. The calendar displays as well as the moon phase indication can be advanced either individually or collectively by depressing the calendar change button in the band. Once correctly set, the date display remains accurate until the next secular year occurs. The moon phase mechanism is also stunningly accurate: after 122.6 years of uninterrupted operation, it deviates from synodic lunation by merely one day. It also features Lange’s patented zero-reset mechanism. The ‘zero-reset’ mechanism simplifies the precise synchronization of the watch to exact time. When the crown is pulled out, it automatically causes the seconds hand to jump to the 12 o'clock or ‘zero’ position so that it can be restarted in exact coordination with a time signal.