Time zone · Americas
UST
Uruguay Standard Time
Uruguay Standard Time (UST) is UTC-03:00, used across all of Uruguay, including Montevideo. Uruguay has not observed daylight saving time since its last summer-time period ended in March 2015, so the offset stays the same all year.
Wednesday, October 14, 2026
Current offset
UTC-03:00
Standard · -03
Daylight saving
Not observed
Year-round standard time
IANA zones
1
None observe daylight saving
DST offset
—
No summer variant
About UST
A fixed, year-round offset.
Uruguay Standard Time (UST) is UTC-03:00, used across all of Uruguay, including Montevideo. Uruguay has not observed daylight saving time since its last summer-time period ended in March 2015, so the offset stays the same all year.
IANA zones · the technical identifiers
The zone that resolve to UST.
For software, always store the IANA identifier — never the abbreviation alone. The database keeps these zones distinct because their rules can, and historically did, diverge.
Cities across UST
Local time, city by city.
1 city
Where UST is used
One country.
Same offset · UTC-03:00
Other zones at UTC-03:00 right now.
These named zones share UST's offset today. When daylight saving rules differ, they drift apart for part of the year.
Convert
UST to the world's clocks.
Frequently asked questions
Common questions about UST, daylight saving, and how to handle it in software. Can't find what you need? Email [email protected].
- Does Uruguay observe daylight saving time?
- No—and it hasn’t since 2015. Its last summer-time period ended on 8 March 2015, and the government then dropped daylight saving time.
- How does UST compare to neighboring time zones?
- It matches Brasília Time (BRT) year-round, making cross-border work with Brazil straightforward—no seasonal misalignment worries.
- Why did Uruguay abolish daylight saving?
- The government dropped daylight saving time in 2015 after concluding it no longer produced meaningful energy savings.
- What is the local standard time in Montevideo?
- Montevideo lives on UTC-03:00 all year; there’s no spring forward or fall back—just consistent -03 for every meeting invite.
- Are there any UST quirks for remote workers?
- Uruguay's own clock never changes, but its time difference with places that use daylight saving time, such as New York or London, still shifts by an hour when those places change their clocks.
- Is there only one official time zone in Uruguay?
- Yes. The entire country uses a single time zone, so every clock in Uruguay shows UTC-03:00.
Source: IANA tzdb2026d · Reviewed
Free · Developer API
This time zone, as JSON.
Its defining offset, DST status and member counts, from one endpoint.
Also in the API: time zones by coordinates, conversions that flag daylight saving gaps, and abbreviations decoded.
Moving off WorldTimeAPI? Our drop-in replacement needs no key.