Time difference between me and Brazil
In August 2016 you are X hours ahead/behind Rio time.
During the Games of the XXXI Olympiad which take place in Rio de Janeiro, Brazil, BRT (Brasilia Standard Time) is in use.
BRT is 3 hours behind UTC (Universal Time Coordinated). In August you are X hours ahead/behind UTC.
So, time difference between your local time and Rio time during Olympic Games is Y hours.
That means you should add/subtract X hours to/from Rio time to get your local time, and subtract/add X hours from/to your time
to get Rio time.