MB&F Reinvents the Perpetual Calendar with Legacy Machine Perpetual Stainless Steel

Since its initial launch in 2015, the LM Perpetual watch has undergone several variations, including red gold, platinum, white gold, titanium, yellow gold, and palladium. However, in 2023, MB&F introduced a new addition to the family: the LM Perpetual Stainless Steel, featuring a unique salmon-coloured plate. This is the first time MB&F has used a steel and salmon combination, and the new edition includes ergonomic corrector pushers previously seen in the LM Perpetual EVO editions.

The Legacy Machine Perpetual is the result of MB&F and independent Irish watchmaker Stephen McDonnell’s effort to reinvent the traditional perpetual calendar complication, resulting in a visually stunning in-house movement that eliminates the disadvantages of typical perpetual calendars. The new movement, powered by a mechanical processor, not only looks exceptional but also allows full appreciation of the dial-side, providing numerous advantages.

LM Perpetual features a fully integrated 581-component calibre − no module, no base movement − with a revolutionary new system for calculating the number of days in each month. And it holistically reinterprets the aesthetics of the perpetual calendar by placing the full complication on a dial-free display underneath a spectacular suspended balance.

The perpetual calendar is one of the great traditional complications, calculating the random complexity of the varying numbers of days in each month − including the 29 days in February during leap years. But traditional perpetual calendars do have a few drawbacks: dates can skip; they are relatively easy to damage if adjusted while the date is changing; and the complications are usually compromises of modules powered by base movements.

The fully integrated, purpose-built movement of Legacy Machine Perpetual has been designed from scratch for trouble-free use: no more skipping dates or jamming gears, and the adjuster pushers automatically deactivate when the calendar changes.

LM Perpetual turns the traditional perpetual calendar system on its head by using a “mechanical processor” instead of the conventional space-consuming grand levier (big lever) system architecture. The mechanical processor utilises a default 28-day month and adds extra days as required. This means that each month always has the exact number of days required; there is no fast-forwarding or skipping redundant days. And while the leap year can only be set on traditional perpetual calendars by scrolling through up to 47 months, LM Perpetual has a dedicated quickset pusher to adjust the year.

With its open dial revealing the full complication and suspended balance, it’s the harmonious mechanical beauty of LM Perpetual that steals the show. And in an interesting technical twist, that eye-catching balance hovering on high is connected to the escapement on the back of the movement by what is likely to be the world’s longest balance staff.

Using an innovative system developed especially for Legacy Machine Perpetual, the subdials appear to “float” above the movement with no visible attachments. The skeletonised subdials rest on hidden studs, which is technically impossible with traditional perpetual calendar mechanisms because they would block the movement of the grand levier.

The Legacy Machine Perpetual won the Best Calendar Watch Prize at the GPHG (Grand Prix d’Horlogerie de Genève) in 2016. MB&F Legacy Machine Perpetual Steel Salmon retails for S$258,000 each (with GST).