TIME · DRIVING · ELECTRICITY · COMMUNICATIONS · CODES
The United States spans several civil time zones, drives on the right, uses a 120 V and 60 Hz electrical system for standard household service, and uses Type A and Type B plugs. This reference also covers live daylight saving status, the +1 calling code, the .us domain, ISO identifiers, measurement practice.
Time-zone notes Each clock is generated in the browser from its own IANA time zone identifier. DST status is calculated independently for every zone. NIST states that most of the United States observes DST, while Hawaii and most of Arizona do not; the Navajo Nation is the Arizona exception. In 2026, DST runs from March 8 to November 1 in observing areas.
Traffic in the United States keeps to the right side of the road, and the driver's position is typically on the left side of the vehicle.
Road traffic keeps right in the United States. Passenger vehicles are normally configured with the steering wheel and driver position on the left.
Measurement: practice US customary units with legal SI use The United States commonly uses US customary units in everyday life, while SI units are legal
| Field | United States | Authority / basis |
|---|---|---|
| Driving side | Right side | Cited road convention |
| Calling code | +1 | ITU |
| ccTLD | .us | IANA Root Zone |
| Measurement practice | US customary units are widely used in everyday life; SI units are legal for trade and commerce. | Cited standards source |
| Mains voltage | 120 V | Cited electrical reference |
| Commercial frequency | 60 Hz | Cited electrical reference |
| ISO alpha-2 | US | ISO 3166 |
| ISO alpha-3 | USA | ISO 3166 |
| ISO numeric | 840 | ISO 3166 |
The source cards below document the United States' cited practical-data fields, including calling code +1, ccTLD .us, and identify the authority used for each claim.