Best overlap: 12:00 PM to 6:00 PM in Rio de Janeiro is 8:00 AM to 2:00 PM in San Francisco.
Your window to reach both cities is 12:00 PM to 6:00 PM in Rio de Janeiro, which converts to 8:00 AM to 2:00 PM in San Francisco. San Francisco is 4 hours behind Rio de Janeiro, yet you get a full 6 hours of shared hours — enough to schedule around lunches, focus time, and preferences with ease. Note the seasonal wrinkle: when San Francisco is on daylight saving and Rio de Janeiro isn't, the gap between them grows or shrinks by an hour.
| Local time | 12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Rio de Janeiro America/Sao Paulo | ||||||||||||||||||||||||
San Francisco America/Los Angeles |
One in San Francisco, one in London, one in Sydney. Many of the best startups are built this way, and many fail because of it. A practical playbook for co-founder relationships across time zones in the first three years. -
An 8 AM Pacific launch is 5 PM in London and 1 AM in Sydney. Your blog post, your engineering on-call, your support team, and your Twitter schedule are all picking different hours. Here is how to plan a launch that does not embarrass you in any time zone. -
8 AM Tokyo is 4 PM in Los Angeles the day before. West Coast afternoon windows, the East Coast dead zone, and why the Philippines slot is an hour off. -