Starting from a blank sheet of paper, MB&F and Irish watchmaker Stephen McDonnell have reinvented that most traditional of horological complications, the perpetual calendar, which can be fully appreciated dial-side beneath the spectacular suspended balance wheel. This architecture is unique to MB&F and truly comes into its own here. Whereas a conventional perpetual calendar subtracts superfluous days from a 31-day month, MB&F's Legacy Machine Perpetual innovates by turning the conventional system Upside Down: a mechanical processor uses a default 28-day month, then adds the required number of days for longer months. This eliminates the risk of causing damage to the mechanism as a result of manipulation or adjustment of the date.