Paris is typically 4 hours ahead of Rio de Janeiro. When it's 10:00 AM in Rio de Janeiro, it's 2:00 PM in Paris. During Central European Summer Time (late March to late October), the difference increases to 5 hours.
Rio de Janeiro uses Brasilia Time (BRT/UTC-3) year-round since Brazil suspended daylight saving time in 2019. Paris follows EU daylight saving rules, using CET (UTC+1) in winter and CEST (UTC+2) in summer.
Optimal meeting window: 8:00 AM - 1:00 PM Rio time (12:00 PM - 5:00 PM Paris). This catches afternoon business hours in Paris while being morning in Rio.
For Paris morning meetings (9:00 AM), Rio participants would need to join at 5:00 AM (winter) or 4:00 AM (summer), which is impractical. Afternoon Paris time offers better overlap.