One of the oldest Swiss watchmaking manufactures, Patek Philippe celebrated its 175th anniversary in 2014 by launching a collection of commemorative pieces including two limited edition world time models for men and women also featuring a moon phase display – a first for the Genevan company.

The world time complication is one of the company’s signature complications, and many consider its earliest wristwatches references – the 1415 and the 2523 – to be some the greatest watches ever produced. We certainly wouldn’t dispute that claim.

Both vintage references were produced from the 1930s to the 1950s thanks to a miniaturized version of a pocket watch movement invented by Louis Cottier, featuring a local time with hour and minute hands at centre, linked to a rotating 24 hour ring, and bordered by a fixed outer dial ring with the names of different cities inscribed on it.

Patek Philippe only began serially producing world time watches again after the turn of the century with the reference 5110, with several special editions made, all featuring a guilloché centre.

For its 175th anniversary, Patek Philippe presented a highly exclusive and more complex “his” and “hers” world timer pair. Available individually, the reference 5575 was limited to 1,300 pieces, while the reference 7175 was limited to 450 pieces.

These new references celebrated the brand’s tradition and its innovative spirit by presenting, for the first time, a world time complication with a large-format and hyper realistic moonphase display. This was made possible thanks to a newly engineered ultra-thin automatic movement, the caliber 240 HU LU, powered by a 22-karat gold microrotor.

The moon itself is richly detailed and is set against a nocturnal starry sky, created by a complex and intricate metallization of the two moonphase discs. Another novelty is that instead of Paris, Geneva represents Central European Time on the external rotating disc, a nod to Patek Philippe's Swiss heritage. The hour hand is in the form of the Southern Cross, a constellation often used for navigation, particularly in the Southern Hemisphere where it is visible for the entire year.

Cased in elegant Calatrava-styled cases in 18k white gold for men and 18k rose gold for women, this extraordinary pair is presented in like new condition, complete with all of its original accessories, and is available for private sale via Phillips PERPETUAL just in time for Valentine’s Day.