Patek Philippe World Time White Gold Ref 5110GThe world timer complication was invented in the 1930s by Louis Cottier; a complication for travellers that needed to know the time in a specific time zone via an outer ring which showed important world time zones. Early Patek world timers had a second crown, but by introduction of ref 5110, a second crown was not needed as Patek introduced a new cal 240 188, where they added a pusher at 11 for moving the inner bezel. There is nothing more satisfying