Patek Philippe Perpetual Calendar Chronograph 5270G Tachy (5270G-013)

The abbreviation for the time zone of the prime meridian, GMT, has also been appropriated to stand as the abbreviation for timepieces that display a second time zone. For the purposes of this review, we take this definition literally and only examine watches that show two different time zones. In a second article we will come back to world time watches, which are capable of showing multiple time zones, or indeed all of the world's time zones, at a glance.

Travel-friendly
For a Patek Philippe timepiece to be travel friendly, it needs more than just a second time zone indication. In the new Nautilus Travel Time Chronograph, which houses an entirely new movement, the choice of case material is equally important. Since the precious metals usually employed in Patek Philippe timepieces may attract unwanted attention in certain tourist destinations, this new model in the Nautilus collection comes in a rare stainless-steel case that is water resistant to 120 metres and cleverly houses the correctors for the dual time zone in its left-hand "hinge", which was specifically redesigned for this purpose.

The new calibre CH 28-520 C FUS self-winding movement combines a chronograph with an intuitive second time zone display. The hour hand of the second time zone is housed on the same axis as that for the home time hour and has the same shape but for the fact that it is skeletonised. Unlike many other GMT watches, the second time zone can therefore remain discreetly hidden until it is needed.

Here and there
For its first-ever dual time model, Van Cleef & Arpels offers a more poetic interpretation of travel and time in its Pierre Arpels "Heure d'ici & Heure d'ailleurs" piece. The French name means simply "Time here & time elsewhere", a concept that is displayed both simply and elegantly by means of two hour discs set at either end of a retrograde minute scale, all of which occupies only half of the dial on this 42mm piece in white gold.

Van Cleef & Arpels developed this new calibre, which is visible through a transparent sapphire crystal, in conjunction with Agenhor. Its two jumping-hour discs are synchronised with the retrograde minutes hand so that all three indications change instantaneously on the hour. A platinum micro-rotor ensures the self-winding function and keeps the case elegantly thin.

Z for Zalium
The latest model in Harry Winston's Project Z series, which uses the brand's exclusive Zalium^TM  alloy (a zirconium-based alloy that is lighter and harder than titanium), also incorporates an innovative second time zone display. The 281 components in the calibre HW3502 movement of the Project Z8 work together to power an off-centre hour and minute display, pointer date, day and night indicator and the signature Shuriken movement operation indicator, as well as a retrograde dual time display that can be corrected in both directions.

In a style typical of the brand, the different time indications have a three-dimensional design, with seven superimposed applied elements used for the reference time indication and a further five interlocking elements used for the GMT display. The Project Z8 is a limited edition of 300 pieces.

Destination outsourcing
For the first collection under its new "Signature" range, which is designed to offer a more accessible alternative to its manufacture movements, Hautlence has turned to Soprod to supply its first-ever externally sourced self-winding movement. As a result, the brand has been able to introduce new functions, such as the disc-based dual time display found in the new Destination collection.

Four different models are available, using variations of steel or titanium cases to frame dials that reflect the brand's architectural DNA and three-dimensional design. This involves a base dial covering the movement which is in turn overlaid with a sapphire intermediate dial on which the Arabic numerals appear to float in space. Note the unique "Horlogerie Suisse" inscription on the dial, with which Hautlence aims to differentiate itself from the Swiss Made, stressing that all parts are developed, produced, decorated and assembled in Switzerland, of which 90% is done in the brand's home canton of Neuchâtel.