No, actually its the anaversary of zaratustras death. Not a celebration of Ahura Mazdah.

You insensitive lout! December 25th is the celebration of Ahura Mazda, the supreme god of Zoroastrianism! Christians appropriated the holiday because many romans and greeks already took the day off.

Next it'll be Frosty banned from holiday scenes in public, seeing how chummy he is with Jesus. Then someone will realize there aren't any Zoroastrian holidays in December or early January, so publicly funded institutions will be forbidden from celebrating “The Holidays” because to do so would display insensitivity toward those for whom The Holidays aren't. At long last we will all be equal and happy.