Boa Vista time zone history
Daylight saving time was used in 6 years since 1970, last in 2000; under the current rules the clocks no longer change. On standard time, clocks in Boa Vista run 3 minutes ahead of local mean solar time.
UTC−4
Standard time is UTC−4 all year under the current rules.
Summer time in 6 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−4:02:40) 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 | not that year | February 7 | 1 hour |
| 1999 | October 3 | not that year | 1 hour |
| 2000 | October 8 | February 27, October 15 | 1 hour |
Also on UTC−4
Guyana, Manaus (Brazil), Venezuela, Barbados, Martinique, Porto Velho (Brazil), Puerto Rico, Dominican Republic, Cuiabá (Brazil) and Bolivia (nearest first; 8 more on the list of offsets).
Clocks next door since 1970
- Guyana (522 km): same time except 7,927 days in 1970–1992, 1999 and 2000.
- Manaus (666 km): same time except 280 days in 1993, 1994, 1999 and 2000.
- Suriname (696 km): usually 1 hour ahead; different on 5,891 days in 1970–1988, 1999 and 2000.
- Santarém (870 km): same time except 6,919 days in 1999, 2000 and 2008–2026; 1 hour ahead today.
- French Guiana (954 km): usually 1 hour ahead; different on 504 days in 1985–1988, 1999 and 2000.
How it compares
Standard time has stayed at UTC−4 since 1914.