| ACT | Acre Time | UTC−5 | (BRT–2) | |
| AMT | Amazon Time | UTC−4 | (BRT−1) | |
| BRT | Brasília Time | UTC−3 | (BRT) | |
| FNT | Fernando de Noronha Time | UTC−2 | (BRT+1) |
Time in Brazil is calculated usingstandard time, and the country (including its offshore islands) is divided into four standardtime zones:Fernando de Noronha time (FNT), UTC−02:00;Brasilia time (BRT), UTC−03:00;Amazon time (AMT), UTC−04:00; andAcre time (ACT), UTC−05:00.[1]About 93% of the Brazilian population live in Brasília time (UTC−03:00).
This is the standard time zone only on a few small offshoreAtlantic islands. The only such island with a permanent population isFernando de Noronha, with 3,167 inhabitants (2022 census), 0.0016% ofBrazil's population.[2] The other islands (Trindade and Martim Vaz,Rocas Atoll andSaint Peter and Saint Paul Archipelago) either are totally uninhabited or have small seasonally rotatingBrazilian Navy garrisons or teams of scientists.
The main time zone of Brazil comprises the states in theSouth,Southeast andNortheast regions (except the small islands mentioned above), plus the states ofGoiás,Tocantins,Pará andAmapá, and theFederal District, which includes the national capital city,Brasília. About 93% of the Brazilian population live in this time zone, which covers about 60% of the country's land area.[2] It includes 26 of the 28largest metropolitan areas in Brazil.
This time zone is used in the states ofMato Grosso,Mato Grosso do Sul,Rondônia,Roraima, and most ofAmazonas. Although this time zone covers about 36% of the land area of Brazil (an area larger thanArgentina), only about 6% of the country's population live there (about 12 million people, slightly more than the city ofSão Paulo).[2] Thus, covering the country's remaining two metropolitan areas (Manaus, Boa Vista).
Until 2008, the areas of the state ofPará west of theXingu River and north of theAmazon River (aka the northwestern part of the said state) were also part of this time zone; then they joined the rest of the state in observing Brasília time (UTC−03:00). Although other changes to Brazilian time zones enacted at that time have since been reverted (see below), western and northern Pará still remain in UTC−03:00.
This time zone was reinstated in late 2013, after having been abolished for over five years. It is used in the far-western tip of the country, which includes the entire state ofAcre and the southwestern portion of the state ofAmazonas (west of a line connecting the cities ofTabatinga andPorto Acre).[a] These areas cover only about 4% of the Brazilian territory (although that is still about the size ofGermany) and have only about 0.5% of the country's population (little more than one million people).[2]
On 24 June 2008, these areas advanced their clocks by an hour, so that they became part of the UTC−04:00 time zone.[7] However, in anon-binding referendum held on 31 October 2010, a slight majority of Acre voters voted in favour of returning the state to UTC−05:00.[8] On 30 October 2013,Brazilian PresidentDilma Rousseff enacted Law 12876, establishing that the time zone switch would occur on Sunday, 10 November 2013.[9] Since then, the state of Acre and the southwestern part of the state of Amazonas[a] are again 5 hours behind UTC.
Unofficially, 32 municipalities in easternMato Grosso,[b] located in theAraguaia valley, observe UTC−03:00, Brasília time.[10][11][12]
Unofficially, some municipalities in easternMato Grosso do Sul, such asBataguassu,Aparecida do Taboado,Cassilândia andChapadão do Sul, also observe UTC−03:00, Brasília time.[13][14]
Brazil observeddaylight saving time (DST;Portuguese:horário de verão, "summer time") in the years of 1931–1933, 1949–1953, 1963–1968 and 1985–2019. Initially it applied to the whole country, but from 1988 it applied only to part of the country, usually the southern regions, where DST is more useful due to a larger seasonal variation in daylight duration. It typically lasted from October or November to February or March.[15]
The most recent DST rule specified advancing the time by one hour during the period from 00:00 on the first Sunday in November to 00:00 on the third Sunday in February (postponed by one week if the latter fell oncarnival), applicable only to theSouth,Southeast andCentral-West regions,[15] which comprise about 65% of the Brazilian population.[2] During DST, Brasília time moved from UTC−03:00 to UTC−02:00; the other states that did not follow DST observed a change of the offset to Brasília time.
Brazil abolished DST in 2019.[15]
TheIANA time zone database contains 16 zones for Brazil. Columns marked with * are from the filezone.tab of the database.
| c.c.* | coordinates* | TZ* | comments* | UTC offset | DST |
|---|---|---|---|---|---|
| BR | −0351−03225 | America/Noronha | Atlantic islands | −02:00 | - |
| BR | −0127−04829 | America/Belem | Pará (east), Amapá | −03:00 | - |
| BR | −0343−03830 | America/Fortaleza | Brazil (northeast: MA, PI, CE, RN, PB) | −03:00 | - |
| BR | −0803−03454 | America/Recife | Pernambuco | −03:00 | - |
| BR | −0712−04812 | America/Araguaina | Tocantins | −03:00 | - |
| BR | −0940−03543 | America/Maceio | Alagoas, Sergipe | −03:00 | - |
| BR | −1259−03831 | America/Bahia | Bahia | −03:00 | - |
| BR | −2332−04637 | America/Sao_Paulo | Brazil (southeast: GO, DF, MG, ES, RJ, SP, PR, SC, RS) | −03:00 | - |
| BR | −2027−05437 | America/Campo_Grande | Mato Grosso do Sul | −04:00 | - |
| BR | −1535−05605 | America/Cuiaba | Mato Grosso | −04:00 | - |
| BR | −0226−05452 | America/Santarem | Pará (west) | −03:00 | - |
| BR | −0846−06354 | America/Porto_Velho | Rondônia | −04:00 | - |
| BR | +0249−06040 | America/Boa_Vista | Roraima | −04:00 | - |
| BR | −0308−06001 | America/Manaus | Amazonas (east) | −04:00 | - |
| BR | −0640−06952 | America/Eirunepe | Amazonas (west) | −05:00 | - |
| BR | −0958−06748 | America/Rio_Branco | Acre | −05:00 | - |