I think the point that EzekielRaiden is making is that when GMs skip ahead for long journeys or those times the characters are sleeping or pooping, they are making that decision for narrative reasons.
A single session only spans days or weeks because the participants are skipping ahead like this. If one were to not do this, each hour of play in real life would equal one hour of activity in the game world. In this way it would be literally (correct use of literally) possible to play out a three week journey in three hour increments over 168 sessions of play. No-one would do it, of course, it would be tedious, but it is literally possible.