Designed with licensed pilots in mind, this model changes the rules. The bezel is engraved with the official IATA codes for the main airports of each timezone. The gold colored outer circle is used for the period from April to October and the silver colored inner circle from November to March. Both circles will automatically account for changes in Daylight Savings Time (summer time). A pleasure for pilots to use, this efficient and highly practical feature is a world’s first in Swiss watchmaking.