Brazil is divided into various time zones. Standard Brazilian time, in the east of the country, is 3 hours behind GMT. In the west, this increases by an hour, so Mato Grosso, for example, is 4 hours behind GMT. In October the clocks go forward an hour for summer. They return to normal around the end of February.
During summer time the country is divided into 4 time zones. Acre, for example, is 3 hours behind Rio, Manaus 2 hours behind and the Northeast (from Recife upwards) is 1 hour behind.
