Historically distinct IANA time zone
America/Porto_Velho
- Countries
- Brazil
- GPS reference
- 8.77° S, 63.90° W
- Data source
- IANA southamerica
- Aliases
- None
- Rule groups
- Brazil
BrazilRondonia
Geographic context
Where this clock belongs
The map marks the IANA reference location and associated country, not a time-zone boundary.
GPS reference: 8.77° S, 63.90° W. Associated countries: BR.
The Wikipedia link provides additional context; it is not evidence for a historical claim. Transition data comes from the IANA source file.
Notes from the time database
The story behind the clock
These source notes describe a period or rule. They do not, by themselves, establish a causal claim for a particular clock change.
Decree 20,466 < (1931-10-01) Decree 21,896 < (1932-01-10)
Original IANA source file: southamerica.
A shared present
Same clock today, different past
These nearby zones follow the same current annual pattern, yet retain their own historical record.
Bolivia · 976 km from the reference location · Same annual clock since 1989Civil-time record
Recorded changes over time
From 1914 to 1988 · 29 recorded transitions
Recurring daylight-saving changes are grouped separately when JavaScript is available.
Notable changes
One-off changes and transitions outside the recurring seasonal rhythm.
- -04:00 · -04Standard time applies
- -03:00 · -03Daylight saving time begins
- -04:00 · -04Standard time applies
- -03:00 · -03Daylight saving time begins
- -04:00 · -04Standard time applies
- -03:00 · -03Daylight saving time begins
Browse every recorded transition
| Local time after transition | Offset after | Abbreviation | Rule |
|---|---|---|---|
| 1914-01-01 00:15 | -04:00 | -04 | Standard time |
| 1931-10-03 12:00 | -03:00 | -03 | Daylight saving time |
| 1932-03-31 23:00 | -04:00 | -04 | Standard time |
| 1932-10-03 01:00 | -03:00 | -03 | Daylight saving time |
| 1933-03-31 23:00 | -04:00 | -04 | Standard time |
| 1949-12-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1950-04-16 00:00 | -04:00 | -04 | Standard time |
| 1950-12-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1951-03-31 23:00 | -04:00 | -04 | Standard time |
| 1951-12-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1952-03-31 23:00 | -04:00 | -04 | Standard time |
| 1952-12-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1953-02-28 23:00 | -04:00 | -04 | Standard time |
| 1963-12-09 01:00 | -03:00 | -03 | Daylight saving time |
| 1964-02-29 23:00 | -04:00 | -04 | Standard time |
| 1965-01-31 01:00 | -03:00 | -03 | Daylight saving time |
| 1965-03-30 23:00 | -04:00 | -04 | Standard time |
| 1965-12-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1966-02-28 23:00 | -04:00 | -04 | Standard time |
| 1966-11-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1967-02-28 23:00 | -04:00 | -04 | Standard time |
| 1967-11-01 01:00 | -03:00 | -03 | Daylight saving time |
| 1968-02-29 23:00 | -04:00 | -04 | Standard time |
| 1985-11-02 01:00 | -03:00 | -03 | Daylight saving time |
| 1986-03-14 23:00 | -04:00 | -04 | Standard time |
| 1986-10-25 01:00 | -03:00 | -03 | Daylight saving time |
| 1987-02-13 23:00 | -04:00 | -04 | Standard time |
| 1987-10-25 01:00 | -03:00 | -03 | Daylight saving time |
| 1988-02-06 23:00 | -04:00 | -04 | Standard time |