Chamonix's winter season can last from the end of December to the beginning of May. The town is easily accessible from Geneva International Airport, in Switzerland, which is about a one hour drive, or via high-speed trains from various destinations in Europe. Once in Chamonix, trains and buses are free within the valley if you hold a ski pass. Buses to the Italian resort Courmayeur are also free with the unlimited ski pass. The language is French; the currency is the euro. Tipping is recommended, unless the service charge is included on the bill. No visa is required for stays up to three months. You may have to show your passport when crossing the border into Italy or Switzerland. Electricity is 220–240 volts.