Thank you Red, I guess I must read and accept the "truth" more carefully!
In all seriousness, both CART and NASCAR do testing/development between races as well. I cannot speak for the level (same, more or less than F1) but they run a fairly rigorous schedule as well. In NASCAR especially there tend to be rule changes about once per week that keep the teams hopping!
Legend, I am sure you would agree that if TGF declared: "There shalt be more time off for Holiday!" That it would be made so immediately (if not sooner!).