IANA tz database · zone identifier

America/Porto_Velho

The IANA tz database identifier for Amazon Standard Time in Brazil. Store this string — not the abbreviation, not the offset — and your timestamps stay correct forever.

UTC-04:00Abbreviation -04No daylight saving
Time in America/Porto_Velho☾ Night
19:00:50
Wednesday, October 14, 2026
Offset
UTC-04:00
Abbreviation
-04
DST
No DST

Current offset

UTC-04:00

same year-round

Abbreviation

-04

tzdb uses numeric abbreviations here

DST behaviour

None

one offset all year

Country

🇧🇷 Brazil

ISO 3166: BR · view country page →

Using this identifier

The string to put in your code.

America/Porto_Velho is the identifier to use in code and config for this region. Every modern language, database, and OS resolves it through the same tz database, so the examples here behave identically everywhere.

Avoid storing -04 or -04:00 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

// format a date in this zone
new Intl.DateTimeFormat('en-US', {
timeZone: 'America/Porto_Velho',
dateStyle: 'full', timeStyle: 'long'
}).format(new Date());

Offset & DST behaviour

One offset,
38 years.

America/Porto_Velho has kept UTC-04:00 year-round since 6 February 1988 — no daylight saving and no offset changes on record since. It is among the most stable identifiers in the database.

Every offset this zone has kept

−04:15:36UTC-04:00 · UNCHANGED 6 February 1988 NOW

Keeping this offset since

6 February 1988

Next transition

None scheduled

no DST rules exist for this zone

Safe to assume

Local = UTC − 4h, always

…but store the identifier anyway

Technical record

The database entry, in full.

source: IANA tz database · release 2026d

IdentifierAmerica/Porto_Velho
ISO country codeBR🇧🇷 Brazil
Reference coordinates8.77°S, 63.90°Wtz database reference point
Standard offsetUTC-04:00abbreviation -04
Daylight offset—no daylight saving time
tzdb release2026ddata current as of this IANA release

Where it applies

One of Brazil's 16 zones.

Looking for travel-friendly info? See Porto Velho or Amazon Standard Time.

🇧🇷
Brazil

214M people, 16 time zones — this identifier covers one of them.

Country page →
🇧🇷 Porto Velho
19:00
19:00:50 · -04
pop. 518KAST

Related identifiers

Nearby in the database.

Same zone group · Amazon Standard Time

other identifiers keeping AST

Same offset · UTC-04:00

other zones keeping this offset right now

Frequently asked questions

Answers specific to this identifier — generated from the database record. Can't find what you need? Email [email protected].

What UTC offset is America/Porto_Velho?
America/Porto_Velho is UTC-04:00, year-round. The offset never changes because the zone does not observe daylight saving time.
Does America/Porto_Velho observe daylight saving time?
No. America/Porto_Velho stays on UTC-04:00 all year, as it has since 6 February 1988.
Which country uses America/Porto_Velho?
Brazil. It is one of 16 IANA zones covering the country.
Is America/Porto_Velho the same as AST?
America/Porto_Velho is one of the IANA zones that keeps Amazon Standard Time (AST). Use America/Porto_Velho in software — AST is a human-friendly label, not a valid identifier.

Free · Developer API

This zone, as JSON.

Its live offset, abbreviation and DST status, plus its coordinates and country, from one endpoint.

GET /v1/timezones Live

Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.

Get your free API key → All endpoints Plans and pricing

Moving off WorldTimeAPI? Our drop-in replacement needs no key.

// this identifier, resolved live
GET /v1/timezones/America/Porto_Velho
{
"data": {
"iana": "America/Porto_Velho",
"observes_dst": false,
"country": { "code": "BR", "name": "Brazil" },
"current": {
"utc_offset": "-04:00",
"abbreviation": "-04",
…
},
…
}
}