MattBrandonThe ring with the cities rotates 360 degrees in one day. You have to set the city ring so that the time in your current city as read on the exterior 24 hour ring equals the time on the main dial (indicated by the hands). In the picture above, that means that the watch is currently set for someone living in Fernando de Noronha island (because current time is 10:10 pm).
Therefore the time in NYC is read next to the NYC : 19:10 pm.