Merry Xmas
When I was a child I was told in was inappropriate and irreverent to write X-mas. The teachers said using the X instead of writing Christ was a way of leaving Christ out of Christmas.
Years later I learned the truth. For one thing the letter X is not the third to the last letter of the English alphabet, like in XYZ. It is a Greek letter, and pronounced chi (ki). And that letter is the first letter of the word Christ in its original Greek language. It legitimately represented the word Kristos or Christ.
So Xmas is in fact Christmas.