I definately have weeks that feel like they are endless! Our usual weekend is taken up with children's activity - Saturday AM, one at Basketball or Soccer, another at Cricket, then dancing. Saturday PM either food essential shopping or cleaning. Sundays is Football (aussie rules) for the oldest boy. In between I will do some work, study, read business related papers, entertain, host at a sporting event or some other business related activity.
The big difference for me is that during the weekdays I am working, whether this is in the office, travelling for work or entertaining at night...I am working. On the weekend it is 'different' work, family activities or sport. So it is different. On weekends we also eat out as a family and make a roast on Sunday, so it's not like the busy weekday experience.
That all said, there are rare days where we don't do anything on a weekend. But they are very rare. Today is one that might fit into that category - we had a sleep in, I went for a 6km run, I made a cooked breakfast & am now just checking emails. For the rest of the day I'm going to take the neighbour to the footy (watching Port v Crows v Carlton) in a corporate box and then will wander home for a roast & movie night with my wife...this is about as much as a doing nothing Sunday that I get!