The LM Perpetual debuted in 2015, with an integrated perpetual calendar designed by Northern Irish watchmaker Stephen McDonnell. The movement uses a “mechanical processor” that views the default number of days in the month as 28 and adds extra days as required by each individual month.
In doing so, the calendar doesn’t skip “redundant” days (as in most calendars), and therefore, there’s no possibility of the date jumping incorrectly. The date can be quick set with a pusher, and a safety prevents any risk of damage if the watch isn’t set correctly. The movement has 72 hours of power reserve and has MB&F’s signature flying balance beating at 18,000 bph.