Debator, the Bible is not silent on these things. Read JWoods post about Romans 14. Read it. Please. You are not to judge those that observe a holy day. Or any other type of day.
For example, one way that first century pagans worshiped their gods was to bring an animal to the temple, dedicate it to their diety, kill it, and eat it. Albert Barnes wrote that some of the animal that had been offered tot he idol was taken to the market and sold with the other meat. Was there a possibility that a Christian could purcahse and eat such meat without contamination? Yes. Paul said that meat offered to idols was "nothing". If it bothered anothers conscience, you were not to eat it in front of them. But it was not violating God's law to do so. Read 1 Cor 10.
The point is, a person does not become a sharer in paganism through contact with the item used in pagan worship. What really distinguishes the Christain from the unbeliever is the willingness to put the needs of others ahead of his or her own.
Debator, you mention the Bible's silence on birthdays as being condemnatory. What about the bible's silence on anniversaries and objects (i.e rings, veils, etc...) used in weddings? Is this not too condemnatory? How do you justify one pagan origin and not the other? You are such a hypocrite.