Abolished in 2019
Brazil ended daylight saving by decree in April 2019, and no transition has taken place since. São Paulo, Rio de Janeiro and Brasília have stayed on UTC-03:00 year round ever since. Older references and stale timezone data will still show a November-to-February summer time that no longer exists.
Why it was dropped
The stated reason was that the electricity savings had disappeared. Brazil's consumption peak had shifted over the preceding two decades from early-evening lighting to afternoon air conditioning, which daylight saving does nothing to reduce. The government also cited the disruption to flight schedules, school timetables and the working day, particularly in the north.
It never applied to the whole country
Even when Brazil did observe daylight saving, the northern and northeastern states were exempt. Near the equator the length of the day barely varies across the year, so shifting the clock achieves nothing. That is the general rule worldwide: daylight saving is a temperate-latitude practice, and tropical countries have largely never bothered with it.