How the case stays slim
World time is built directly into the base calibre. Its height is 4.75 mm in the specifications, rounded to 4.8 mm in the description. That matters for a complicated watch: the extra function does not need a tall separate module.
Moving to another time zone
Press the case button and the hour hand and city disc move together. A separate, single-hand 24-hour scale retains the second time, making day and night easy to distinguish.
What lies behind world time
Inside is NOMOS’s proprietary swing system escapement with a blue hairspring. The rotor winds in both directions. The calibre has stop-seconds and 37 jewels and is adjusted in six positions. Its reserve of up to 42 hours means it is best not to leave the watch unworn for too long between trips.
Why it is interesting
The DUW 3202 has a pleasing control logic: change the city with a button and immediately get local time without touching the home-time scale. The calibre’s thickness shows how compactly the system was assembled.
Things to consider
A 42-hour reserve cannot cover two full days off the wrist. A slim calibre does not tell the whole fit story either: check the case length and lugs of the particular Worldtimer.