Independent watchmaker MB&F’s incredibly complex Legacy Machine Perpetual returns to this year’s Salon International de la Haute Horlogerie (SIHH) with two new faces. A purple face and a grey face, both encased in white gold, are the newest additions to the Legacy Machine collection. While the purple face is limited to 25 pieces, the grey face is an unlimited piece and is the only version in the collection to be so. This is an extension of the brand’s Legacy Machine Perpetual collection, which was first launched in 2015 and came in two versions: red gold and platinum.

The LM Perpetual won the Calendar Watch Prize at last year’s Grand Prix d’Horlogerie de Genève, a testament to the engineering feat required from the watchmakers at MB&F to create the complication.

MB&F’s Legacy Machine Perpetual, winner of the Grand Prix d’Horlogerie de Genève, is fool-proof

The LM Perpetual boasts a fully integrated calibre made up of no less than 581 components housed inside a skeleton case. The biggest accomplishment the LM Perpetual boasts is the way it has differentiated itself from its competitors by reinventing the method for counting the number of days each month to compensate for leap years. Instead of using a “grand levier” (or “big lever”) to measure the months in the traditional way, the clever people at MB&F have managed to come up with a mechanical processor to count the days in a new way.

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In the traditional way, all months start at a default of 31 days with one, two or three days taken off depending on the month and leap year. But MB&F’s mechanical processor is engineered in a way so that the default number of days in any given month is 28 days. The days are then added, depending on the month and leap year.

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“With the conventional system, we’ve got everything based on 31 days. You’re always obliged to move through the 31 days even if you don’t use your 31 days,” says Stephen McDonnell, master watchmaker of MB&F, in the brand’s first video explaining the beauty of LM Perpetual’s new mechanical processor.

“I wanted to create a calendar which will jump precisely from the last day of the month, be it 28, 29, 30 or 31, directly to the first with no hesitation or passing over unwanted days and this we managed to achieve.”

Watch the video below to find out what differentiates MB&F’s perpetual calendar and puts it in a class of its own.

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