The U.S. dollar is the official currency of the United States and is normally abbreviated as the dollar sign, $, or as USD or US$. It is divided into 100 cents. Current exchange rates can be found online at: http://www.xe.com/ucc/
United States operates 110 volts AC, 60 hertz electricity which is half of the 220 volts that many other countries use. Dual voltage appliances with plug type A are recommended.
Pacific Daylight Time (PTD) or GMT -7 hours
English is the official language of the Congress.
Tipping in the United States is not mandatory. The suggestions below are customary and you may tip at your discretion.
Restaurants with table service: A 15% - 20% tip is customary in restaurants that provide table service. The tip should reflect the level of service you receive. Restaurants will often include the gratuity, or tip, in large parties of 6 or more. If the tip is included, the bill will include a "gratuity” charge in the breakdown. If a “gratuity” charge is included on your bill, you do not need to leave an additional tip.
Taxi: 10 - 15% of the total fare
Bellman: $1 USD / bag