Introduced in 2011, the Nomos Xi movement adds a world timer function between the bottom plate of the movement and the dial. This function consists of an outer disc with city names or airport codes for each timezone and a 24 hour wheel at 3:00 for "home time". It is operated by means of a pusher located at 2:00 and adjusted with a second pusher at 8:00 set flush with the case. Each time the main pusher is depressed, the central hour hand and location wheel advances by an hour. The second pusher advances the central hour hand separately from the location wheel, allowing it to be "calibrated" for the base timezone.
Nomos Xi is used in two watches:
- Nomos Zürich Weltzeit - A full city wheel around the periphery of the dial
- Nomos Tangomat GMT - A GMT window with airport codes at 9:00
- Nomos Tangomat GMT Plus - A GMT window with simple "+/-" hour indicators at 9:00