South America contains 18 time zones that are either two, three, four, five or 4 1/2 hours earlier than Greenwich Mean Time. Most countries operate with a single time zone, although Brazil uses two.
Seven of the time zones in South America observe daylight savings time, offsetting them from GMT by one less hour. Argentina, parts of Brazil, French Guiana, Suriname and Uruguay are typically three hours earlier than GMT. During daylight savings time, Uruguay and parts of Brazil are only two hours earlier than GMT. Peru, Colombia and Ecuador are five hours earlier than GMT, while Bolivia, part of Brazil, Chile, the Falkland Islands, Paraguay and Guyana are four hours earlier.