12 hours bezel watches
The 12-hour bezel is the simplest way to track two time zones on a watch. While a GMT watch requires a caliber with a specific complication to track a second time zone, a 12-hour bezel achieves a similar result using a regular caliber without special features.
The bezel itself is a regular, usually bidirectional bezel, similar to those found on dive watches, but with 12 hours marked on it. By aligning the second time zone's current hour to the hour hand, you can easily track the secondary time.
The downside of this type of bezel is that it doesn't account for AM/PM differences. However, it compensates for this limitation by being more affordable and easier to set.
The bezel can also track elapsed hours, much like how a dive bezel tracks elapsed minutes. Simply align the 0/12 hour marker with the current position of the hour hand to use this feature.
