(slow scroll to interact)
Local time is indicated by:
The local hour hand on the 12-hours indices for hours
The local minute vertex on the 12-hour indices for minutes
Displayed time: 10:09 (AM)
There are few moments in horological history that evolve the art of timekeeping. The pioneering of the mechanical GMT movement in 1954 was one of them. For the first time, you could be away from home but carry its time with you.
The GMT movement was built on the foundations of Greenwich Meridian Time, conceived in 19th century Britain. But the mechanical GMT movement excludes about 1.6 billion people in 10 countries around the world. These countries have a unifying feature: they are non-standard GMT zones which can only be expressed in 30 or 45 minute offsets to the standard whole-hour GMT zones.
Indian Standard Time, for example, is GMT+5:30. Australian Central Standard Time would be GMT+9:30. If you were flying to Nepal (GMT+5:45) from Switzerland (GMT+1), you couldn't tell time in both places with your traditional GMT watch. Horology has seen efforts to capture these rogue time zones since 1954, but never as something more than a mechanical afterthought.