High Quality Content by WIKIPEDIA articles! Coordinated Universal Time (abbreviated UTC) is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose. If only limited precision is needed, clients can obtain the current UTC time from a number of official internet UTC servers. For sub-microsecond precision, clients can obtain the time from satellite signals. Time zones around the world are expressed as positive or negative offsets from UTC, as in this list.