DEPENDS WHAT YOU THINK TAROT IS
I guess it depends how you view tarot and your religion (if you have any).
Do you consider you're doing something wrong or against the will of the Divine when reading? If yes, then maybe "holy days" should be left out. Or maybe you'll need to reconsider what tarot is - is it something sinful and wrong to be hidden from the 'eyes of the divine'? Why? Why not?
Do you feel you're working while reading, whereas your religion's god forbids working on certain days? Then yes, maybe leave these rest days out.
If you think tarot is direct communication with higher beings/the divine/angels/something along these lines, wouldn't it make most sense to read on holy days when the connection could be seen "enforced"?
In any other (and in my own) case, I can't see why readings could not be done day and night, Christmas, Easter and Halloween and anything in between.