Swiss watchmaker MB&F, creator of what the brand prefers to call “horological machines” as opposed to simply wristwatches, recently released perhaps its most complicated piece to date: the Legacy Machine Perpetual. The new model in the brand’s Legacy Machine line features a 581-component perpetual calendar caliber with a revolutionary new way for calculating the number of days in each month. Unlike traditional perpetual calendars which use a 31-day month as the default and remove superfluous days for months with fewer days by essentially fast-forwarding through extra days during changeover, MB&F’s utilizes a “mechanical processor,” a stacked-gear system, in lieu of the conventional grand levier, which assumes a default 28-day month and adds extra days as required. As a result of this, each month has exactly the number of days required, so there is no fast-forwarding or skipping through days, minimizing the risk of the date jumping incorrectly.

mbandf.com