With regard to your comments surrounding a National Day of Reason, it sounded like, and I hope I am wrong, that you believe reason and religion have faith in common. I could not disagree more. Reason is based in evidence, the scientific method, and its claims are falsifiable. The same cannot be said for religion. Just as no one can prove that Santa Claus or the Tooth Fairy does not exist, no one can prove that God does not exist because these are supernatural entities and one cannot prove a negative. Thus, the existence or nonexistence of supernatural entities is not a testable or falsifiable hypothesis. On the other hand, one can prove (in a probabilistic as opposed to an absolute sense -- a notion connected to the falsifiability that is the backbone of the scientific method) that a particular drug is effective in treating a particular condition. This is not a matter of faith. It is a matter of empirical evidence.
As to the holiday itself, I am very much in favor of providing the people with a "day off" (as opposed to calling it a "holiday," which, as you point out, is a term with religious roots) in the name of reason because it is an opportunity to highlight an idea whose presence plays an integral role in the health of our nation and whose absence undermines the pursuit of the fair, just, and sustainable future that I know you and I both would like to see. Further, Americans are overworked and overstressed relative to their Western European brothers and sisters, so one more day off would be a step in the right direction. I write that only half tongue in cheek because, as you know, American productivity has steadily risen, while wages have remained stagnant since the 1970s, all while the French moved to a 35-hour work week, the Spanish take daily siestas, and the European community granted their citizens at least 4 weeks of vacation per year by law, laws which are present in one form or another in every industrialized nation but one. Which one might that be? You guessed it. The good ole US of A.