Hmm, interesting.
I live in a place where hot water is either from a continuous flow heater, so basically no extra circulation; or from a small under-sink water heater where the water is kept at safe temperature and the distance to the tap is near zero.
But I guess in places with these big, central hot water storage thingies what the article says makes sense.
So, when someone asks if you are free the next two weekends, you assume they're talking about the next Saturday (tail weekend) and the next Sunday (front weekend)?