Cuiabá time zone history
Daylight saving time was used in 35 years since 1970, last in 2019; under the current rules the clocks no longer change. On standard time, clocks in Cuiabá run 16 minutes behind local mean solar time.
UTC−4
Standard time is UTC−4 all year under the current rules.
Summer time in 35 of 57 years since 1970
Before 1970
Standard time changes
| Date | Change | New standard time | Clock label |
|---|---|---|---|
| Before 1970 | |||
| January 1, 1914 | Local mean time (UTC−3:44:20) replaced | UTC−4 | numeric only |
Daylight saving periods
| Years | Clocks go forward | Clocks go back | Shift and labels |
|---|---|---|---|
| Before 1970 | |||
| 1931 | October 3 | not that year | 1 hour |
| 1932 | October 3 | April 1 | 1 hour |
| 1933 | not that year | April 1 | 1 hour |
| 1949 | December 1 | not that year | 1 hour |
| 1950 | December 1 | April 16 | 1 hour |
| 1951–1952 | 1 December, 00:00 | 1 April, 00:00 | 1 hour |
| 1953 | not that year | March 1 | 1 hour |
| 1963 | December 9 | not that year | 1 hour |
| 1964 | not that year | March 1 | 1 hour |
| 1965 | January 31, December 1 | April 1 | 1 hour |
| 1966–1967 | 1 November, 00:00 | 1 March, 01:00 | 1 hour |
| 1968 | not that year | March 1 | 1 hour |
| Since 1970 | |||
| 1985 | November 2 | not that year | 1 hour |
| 1986 | October 25 | March 15 | 1 hour |
| 1987 | October 25 | February 14 | 1 hour |
| 1988 | October 16 | February 7 | 1 hour |
| 1989 | October 15 | January 29 | 1 hour |
| 1990 | October 21 | February 11 | 1 hour |
| 1991 | October 20 | February 17 | 1 hour |
| 1992 | October 25 | February 9 | 1 hour |
| 1993 | October 17 | January 31 | 1 hour |
| 1994–1995 | third Sunday in October, 00:00 | third Sunday in February, 00:00 | 1 hour |
| 1996 | October 6 | February 11 | 1 hour |
| 1997 | October 6 | February 16 | 1 hour |
| 1998 | October 11 | March 1 | 1 hour |
| 1999 | October 3 | February 21 | 1 hour |
| 2000 | October 8 | February 27 | 1 hour |
| 2001 | October 14 | February 18 | 1 hour |
| 2002 | November 3 | February 17 | 1 hour |
| 2003 | not that year | February 16 | 1 hour |
| 2004 | November 2 | not that year | 1 hour |
| 2005 | October 16 | February 20 | 1 hour |
| 2006 | November 5 | February 19 | 1 hour |
| 2007 | October 14 | February 25 | 1 hour |
| 2008–2011 | third Sunday in October, 00:00 | third Sunday in February, 00:00 | 1 hour |
| 2012 | October 21 | February 26 | 1 hour |
| 2013–2014 | third Sunday in October, 00:00 | third Sunday in February, 00:00 | 1 hour |
| 2015 | October 18 | February 22 | 1 hour |
| 2016–2017 | third Sunday in October, 00:00 | third Sunday in February, 00:00 | 1 hour |
| 2018 | November 4 | February 18 | 1 hour |
| 2019 | not that year | February 17 | 1 hour |
Also on UTC−4
Campo Grande (Brazil), Porto Velho (Brazil), Bolivia, Manaus (Brazil), Boa Vista (Brazil), Santiago (Chile), Guyana, Venezuela, Barbados and Martinique (nearest first; 8 more on the list of offsets).
Clocks next door since 1970
- Campo Grande (563 km): same time except 119 days in 2003 and 2004.
- Paraguay (1,089 km): same time except 5,641 days in 1972–2026; 1 hour ahead today.
- Porto Velho (1,138 km): same time except 3,671 days in 1988–2019.
- Araguaína (1,267 km): usually 1 hour ahead; different on 2,287 days in 1985–2019.
- Bolivia (1,293 km): same time except 4,021 days in 1985–2019.
How it compares
Standard time has stayed at UTC−4 since 1914.
Clocks have been changed 66 times since 1970, the third-most of the 16 zones in Brazil.