You know neither the origins nor the reasons for the religion based holidays. Some are fixed to the calendar; some are calclated with formulae and are "movable." Presidential decree will not avail those who would arrange them for convenience. The Church does not properly accomodate itself and its practices to the whims of governments of men.
Thanksgiving is not a Church ordained holiday but a secular holiday for religious reasons.
LOL!
I know the origins fairly well, fellah.
4 years of religious studies in a Jesuit High School, followed by four years of Classical and Medieval History in college, concentrating on Rome and including the history of the Church.
Try again.