So what they do is, let's say you take two people who meet up, and they take the number of days those two people spent together, and then they estimate how many hours were in those days -- how many hours did those two people spend together?
No Couchsurfing, digamos  que duas pessoas se conheceram. Eles contam o número de dias  que as duas pessoas passaram juntas, estimam quantas horas havia naqueles dias, quantas horas as duas pessoas passaram juntas,