GMT to BRT Converter
Convert time between Greenwich Mean Time (GMT) and Brasilia Time (BRT)
Greenwich Mean Time (GMT)
Brasilia Time (BRT)
Time Difference
Brasilia Time (BRT) is 0 hours ahead of Greenwich Mean Time (GMT)
Select Date
Select Time
Quick Reference
| GMT | BRT |
|---|---|
| 03:00 | 23:00 |
| 05:00 | 01:00 |
| 07:00 | 03:00 |
| 09:00 | 05:00 |
| 11:00 | 07:00 |
| 13:00 | 09:00 |
| 15:00 | 11:00 |
| 17:00 | 13:00 |
| 19:00 | 15:00 |
| 21:00 | 17:00 |
| 23:00 | 19:00 |
| 01:00 | 21:00 |
Top 10 Most Common Time Zones
| Abbreviation | Full Name | UTC Offset | Typical Use |
|---|---|---|---|
| UTC | Coordinated Universal Time | UTC ±0 | Global reference standard (servers, logs, APIs) |
| EST / EDT | Eastern (US) Time | UTC −5 / −4 | New York, Toronto — North American business hub |
| CST / CDT | Central (US) Time | UTC −6 / −5 | Chicago, Dallas — US central business region |
| PST / PDT | Pacific (US) Time | UTC −8 / −7 | San Francisco, Los Angeles — tech industry standard |
| GMT / BST | Greenwich Mean / British Summer Time | UTC 0 / +1 | UK, used globally as a reference with UTC |
| CET / CEST | Central European (Summer) Time | UTC +1 / +2 | Paris, Berlin, Amsterdam — EU business core |
| IST | India Standard Time | UTC +5:30 | India — major IT & outsourcing region |
| CST | China Standard Time | UTC +8 | Beijing, Shanghai — East Asia business hub |
| JST | Japan Standard Time | UTC +9 | Tokyo — finance & tech hub |
| AEST / AEDT | Australian Eastern (Daylight) Time | UTC +10 / +11 | Sydney, Melbourne — APAC regional business |
Why Time Zone Abbreviations Are Ambiguous
Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).
Common Ambiguous Time Zone Abbreviations
| Abbrev. | Common Meaning(s) | UTC Offset | Region(s) |
|---|---|---|---|
| CST | Central Standard Time / China Standard Time / Cuba Standard Time | UTC−6 / UTC+8 / UTC−5 | North America, China, Cuba |
| IST | Indian Standard Time / Irish Standard Time / Israel Standard Time | UTC+5:30 / UTC+1 / UTC+2 | India, Ireland, Israel |
| AST | Atlantic Standard Time / Arabia Standard Time | UTC−4 / UTC+3 | Caribbean, Canada, Middle East |
| PST | Pacific Standard Time / Philippine Standard Time | UTC−8 / UTC+8 | North America, Philippines |
| EST | Eastern Standard Time (North America / Australia) | UTC−5 / UTC+10 | North America, Australia |
✅ Best Practice
To avoid ambiguity, always:
- Use IANA tz identifiers — e.g.,
America/New_Yorkinstead of "EST" - Specify UTC offset explicitly — e.g.,
UTC−5when abbreviations must be used - Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset
About GMT to BRT Time Conversion
Converting between Greenwich Mean Time (GMT) and Brasilia Time (BRT) connects the United Kingdom, Iceland and parts of West Africa with Brazil. GMT is UTC+0 and BRT is UTC-3, putting Sao Paulo, Rio de Janeiro and Brasilia 3 hours behind London, Reykjavik, Dublin (in winter), Lisbon (in winter) and Accra.
This converter uses the IANA timezone database for accurate calculations. The UK observes GMT from the last Sunday in October to the last Sunday in March; in summer it switches to BST (UTC+1) and the gap to BRT becomes 4 hours. Iceland and several West African countries stay on GMT/UTC year-round.
Common Use Cases for GMT to BRT Conversion
Business & Work
- Coordinating finance and trade calls between London and Sao Paulo during the UK winter
- Scheduling year-round meetings between Reykjavik or West African capitals and Brazil
- Aligning logistics handovers across the South Atlantic
Personal & Travel
- Planning travel between the UK, Iceland, Portugal or West Africa and Brazil
- Coordinating with family or friends in Sao Paulo, Rio de Janeiro or Brasilia
- Scheduling video calls during the UK winter months
Time Zone Information
Greenwich Mean Time (GMT)
- UTC Offset: UTC+0
- IANA Timezone: Europe/London
- Daylight Saving: UK/Ireland: switch to BST/IST (UTC+1) from late March to late October. Iceland, Ghana, Senegal: never observed.
- Major Cities: London, Dublin, Lisbon, Reykjavik, Accra, Dakar
- Coverage: United Kingdom and Ireland in winter; Iceland and several West African nations year-round
Brasilia Time (BRT)
- UTC Offset: UTC-3
- IANA Timezone: America/Sao_Paulo
- Daylight Saving: Not observed (DST abolished in Brazil in 2019)
- Major Cities: Brasilia, Sao Paulo, Rio de Janeiro, Belo Horizonte, Salvador
- Coverage: Most of Brazil including the southeast, south, northeast and central-west regions
Quick Reference: GMT to BRT
Remember: BRT is 3 hours behind GMT during the UK winter and year-round in Iceland and parts of West Africa
Frequently Asked Questions
What is the time difference between GMT and BRT?
Greenwich Mean Time (GMT) is UTC+0, and Brasilia Time (BRT) is UTC-3. BRT is 3 hours behind GMT. When it is 12:00 PM in London, it is 9:00 AM in Brasilia.
When does this GMT to BRT conversion apply?
The UK and Ireland observe GMT from the last Sunday in October to the last Sunday in March. Outside that window, they switch to BST/IST (UTC+1), and the gap to BRT grows to 4 hours. Iceland and several West African countries stay on GMT/UTC year-round.
How does the time difference change throughout the year?
For the UK, the offset is 3 hours in winter and 4 hours during the summer when the country is on BST. For Iceland and Ghana the 3-hour gap is constant. Brazil ended DST in 2019, so the Brazilian side never shifts.
What are the best times for GMT-BRT business calls?
A 3-hour gap leaves a comfortable mid-day overlap. A London afternoon (1:00 to 4:00 PM GMT) lines up with a Brazilian morning (10:00 AM to 1:00 PM BRT). For end-of-day handovers, 5:00 to 6:00 PM GMT maps to 2:00 to 3:00 PM BRT.
Which countries/regions use BRT timezone?
BRT is observed across most of Brazil, including Brasilia, Sao Paulo, Rio de Janeiro, Belo Horizonte and Salvador. A few western Brazilian states use AMT (UTC-4) instead.
Which countries/regions use GMT timezone?
GMT is observed in the UK and Ireland in winter, plus Iceland, Ghana, Senegal and several other West African nations year-round. Major cities include London, Dublin, Lisbon (winter), Reykjavik, Accra and Dakar.
Pro Tips
- • BRT is 3 hours behind GMT — subtract 3 hours from a London time to get the Brasilia time.
- • When the UK switches to BST in late March, the offset grows to 4 hours until late October.
- • Iceland and several West African countries stay on GMT all year — the 3-hour gap is constant for those regions.
- • Brazil does not observe DST, so any seasonal change comes from the European side.
- • Use IANA identifiers (Europe/London, Atlantic/Reykjavik, Africa/Accra, etc.) in calendars to handle DST transitions correctly.
- • A London afternoon to early evening pairs cleanly with the Brazilian late morning to early afternoon.