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?
Dělají to takhle: Představte si dva lidi, kteří se potkají, a oni vezmou počet dnů,  které tito dva spolu strávili, a potom odhadnou, kolik to asi bylo hodin - kolik hodin strávili tito dva lidé spolu.