I would say, though, to your further point, that it is not in the interests of communication for anyone who reveres Christ to use the abreviation. His odds of being understood are slim, at best. He'll be taken as meaning the same thing as everyone else means by it: a cutesy, Christless abbreivation... like saying "Turkey Day" instead of Thanksgiving.
Dan
I detest that.
But I would point out that it's entirely appropriate for many of the people I know because for them, there is no giving thanks, there is no God, there is no prayer.
For them, it's just "turkey day". What a pity for them.