Why Latin American business runs on two clocks
A bank in Brickell opens at 08:00 Eastern. Its São Paulo desk has already been working for an hour. By the time the Miami team takes lunch, the Mexico City office is mid-morning. The differences are never more than two hours, but they flip direction and shift twice a year. Miami firms that serve the region keep two schedules: one for Eastern Time, one for the local time of the client on the other end.
That dual reality is the daily operating rhythm for law firms, trading desks, freight forwarders and tech offices that use Miami as their Latin American base.
Which cities run ahead and which run behind Miami Latin America time zones
All times below are relative to Miami. A positive number means the city is ahead; a negative number means it is behind.
| City | IANA zone | Offset from Miami (EDT/EST) |
|---|---|---|
| São Paulo | America/Sao_Paulo | +1h (EDT) or +2h (EST) |
| Buenos Aires | America/Argentina/Buenos_Aires | +1h (EDT) or +2h (EST) |
| Santiago | America/Santiago | +0h (EDT) or +1h (EST) |
| Bogotá | America/Bogota | 0h (EDT) or +0h (EST) |
| Lima | America/Lima | 0h (EDT) or +0h (EST) |
| Quito | America/Guayaquil | 0h (EDT) or +0h (EST) |
| Mexico City | America/Mexico_City | -1h (EDT) or 0h (EST) |
| San José (Costa Rica) | America/Costa_Rica | -1h (EDT) or 0h (EST) |
| San Salvador | America/El_Salvador | -1h (EDT) or 0h (EST) |
| Caracas | America/Caracas | 0h (EDT) or +0h (EST) |
During EDT (second Sunday March to first Sunday November), Miami is UTC-4. During EST (first Sunday November to second Sunday March), Miami is UTC-5.
The gap for São Paulo and Buenos Aires is not constant. It widens by an hour when Miami falls back to EST.
Mexico and Central America: the cities that sit behind Miami
Mexico City, San José and San Salvador
Mexico City, San José and San Salvador are the only major Latin American business capitals that can lag Miami. During EDT (March to November), they are one hour behind. During EST (November to March), they match Miami exactly.
Mexico abandoned DST nationwide in 2022, returning to standard time permanently. One exception: Baja California still observes DST to align with California.
What the flip means for a call
In July (EDT): 10:00 Miami is 09:00 Mexico City. In January (EST): 10:00 Miami is 10:00 Mexico City.
A Miami trader calling Mexico City in summer gets an extra hour before the counterparty’s market opens. In winter, the clocks are identical and the morning rush happens simultaneously.
South America: the 0-to-2-hour spread
São Paulo and Buenos Aires
These are the two largest financial centers in the region. Both stay on standard time year-round. Brazil stopped DST in 2024. Argentina has not observed it since 2010.
When Miami is on EDT (March to November): São Paulo and Buenos Aires are +1 hour ahead. When Miami is on EST (November to March): São Paulo and Buenos Aires are +2 hours ahead.
Santiago
Chile still observes DST, but on a roughly opposite schedule. It springs forward in September and falls back in April. That creates brief windows where Santiago is zero or one hour ahead of Miami.
Bogotá, Lima, Quito and Caracas
These four capitals sit at UTC-5 and do not observe DST. They are always the same time as Miami during EST, and one hour behind during EDT.
Who still changes clocks and who does not
Assuming everyone changes clocks on the same day is the single biggest scheduling error in the hemisphere.
| Country | DST observed? | Typical schedule |
|---|---|---|
| United States (Miami) | Yes | Second Sunday March, first Sunday November |
| Canada (Toronto, Vancouver) | Yes | Same as US |
| Brazil | No (stopped 2024) | Year-round BRT (UTC-3) |
| Argentina | No (stopped 2010) | Year-round ART (UTC-3) |
| Chile | Yes | September, April (opposite) |
| Colombia | No | Year-round COT (UTC-5) |
| Peru | No | Year-round PET (UTC-5) |
| Mexico | No (stopped 2022) | Year-round CST (UTC-6) |
| Central America (Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama) | No | Year-round standard time |
In January, Miami and Mexico City share the same clock. In July, they are an hour apart. In October, Miami and Buenos Aires are one hour apart; in December, two.
What a bilingual bi-zonal office in Miami Latin America time zones runs in a day
Miami firms serving Latin America run two schedules. A typical day:
- 07:30 Miami: pre-market calls with Mexico City (08:30 Mexico City during EST, 07:30 during EDT).
- 09:00 Miami: open of NYSE and NASDAQ (09:30 Eastern).
- 10:00 Miami: standard call window with São Paulo (11:00 BRT) and Buenos Aires (11:00 ART).
- 12:00 Miami: lunch. Many offices close for 60 to 90 minutes, mirroring Latin American practice.
- 14:00 Miami: afternoon calls with Santiago or Lima.
- 17:00 Miami: close of US equity markets at 16:00 Eastern. After-hours trading available on many platforms.
The overlap window
A law firm with offices in Miami and São Paulo may set its Miami team to 08:00 to 17:00 EDT and its São Paulo team to 09:00 to 18:00 BRT. That gives a 4-hour overlap: 10:00 to 14:00 Miami, 11:00 to 15:00 São Paulo. During EST, the overlap shrinks to 3 hours.
Market hours: NYSE against Latin American exchanges
| Exchange | Local time | Miami time (EDT) | Miami time (EST) |
|---|---|---|---|
| NYSE / NASDAQ | 09:30-16:00 Eastern | 09:30-16:00 | 09:30-16:00 |
| Brazil B3 | 10:00-17:00 BRT | 09:00-16:00 | 08:00-15:00 |
| Mexico BMV | 08:30-15:00 CST | 09:30-16:00 | 08:30-15:00 |
| Argentina BYMA | 10:00-17:00 ART | 09:00-16:00 | 08:00-15:00 |
Pre-market and after-hours trading on US exchanges runs from 04:00 to 20:00 Eastern. That can fill gaps when Latin American markets are open but US markets are not.
How to pick a recurring time that works in both seasons
Pick a slot that holds across EDT and EST. The safest window: 10:00 to 12:00 Miami. That is 11:00 to 13:00 in São Paulo and Buenos Aires, and 09:00 to 11:00 in Mexico City. It clears market opens and lunch breaks at both ends.
For city-specific times and converters: - Miami vs São Paulo time - Miami vs Mexico City time - Miami vs Buenos Aires time - Business hours in Miami