Breguet Classique Hora Mundi 5717 is the first mechanical timepiece with an instant-jump time zone display that works at the push of a button…
When you see a star, you know it by its looks. Breguet’s Classique Hora Mundi 5717 is a star: for it is the first example of a mechanical timepiece with an instant-jump time zone display. All of the displays jump between time zones with the push of a button. So intuitive is the concept, you wonder why it has not been done before?
The watch shows the world a new approach to the so-called World Timer (a clock with all time zones covered in its own bezel and dial). This watch is not equipped with traditional hand auxiliary hours generally used to indicate the second time zone. Equipped with a GMT special module that allows you to set your time zone, this is home to the second area to which you are interested. At this point there will be more to do, but move smoothly from one to another with a single push of button, located at 8 am. The module in question works so perfectly to even activate the indicator of night and day, combining functionality and beauty in one movement. The instantjump time zone feature with fully-synchronised displays is the showstopper. This is a world-first for a mechanical watch, and indeed this timepiece has generated four patent applications.
From among the 24 available time zones, the wearer pre-selects two cities for which he wishes to display local time. Once set, he can instantly change all displays from one city to the other by pressing on the combined crown/pushpiece at 8 o’clock.
To avoid any confusion in reading the date, Breguet’s watchmakers have added a tiny retrograde hand, hidden beneath the dial except for the tip, and ending in a small circle that surrounds the date as soon as it appears at the left side of the date window. The hand follows the date through the day until it disappears at the right side of the window. At midnight, the hand jumps back to the left side of the window to indicate the date of the day just beginning.
The Hora Mundi also offers an original date display that makes use of a dragging disc. The disc appears in a window on the dial at 12 o’clock. The window is large enough to show threeconsecutive dates at once.
Coming back to Hora Mundi’s four patent applications claim, here are the ones:
1) a timepiece comprising a mechanism with two time zones,
2) the display of a time zone on demand via the main set of hands,
3) a programmable and reprogrammable mechanical memory wheel for a timepiece, and
4) a mechanism for displaying a temporal dimension by means of a dragging hand.
The Hora Mundi case measures 44mm in diameter by 13.55mm thick, and is available in 18-carat red gold or 950 platinum, both watertight to 30 meters. The hands run over a solid gold dial available in three versions: the Americas, the European and African continents, or Asia and Oceania.
The dial’s periphery has a silvered and circular satin-brushed finish, a border that is hand-engraved on a rose engine, and red-gold hour markers – or platinum, depending on the case version. The dial’s centre, depicting a view of the globe, is stamped and hand-engraved on a rose engine to create a ‘wave’ motif on the oceans. The oceans are then given multiple coats of lacquer and the continents are polished. On the day/night indicator, the sky is made of lapis lazuli containing numerous pyrite inclusions that look like tiny specks of gold and represent the stars. The sun and moon are made of solid gold: yellow gold for the sun, rhodium-plated yellow gold for the moon. The cover for this disc, representing a cloud and bearing the Breguet name and the watch’s serial number, is also made of silvered 18-carat gold and engraved entirely by hand.