I like this day as well as the other holidays he recommends. ("Revise your New Years Resolutions day", Bullcrap Day, Little Victories Day and Turing's Birthday seem relevant).

According to this comic, my birthday is "Bullcrap Observance Day":

Bullcrap Observance: This day is to remember that you should always take into consideration what you see and hear, held on the anniversary of Nixon’s “I am not a crook” speech. In commemoration, contribute fake facts and stories in conversation, try to slip complete fiction past others – and take everything you receive with a hearty grain of salt.

I guess that's a nice rationalist-y holiday . . .