Answer:
"Merry Christmas"
Chag Molad Sameach

חג מולד שמח
Chag basically means holiday or "festival." Molad generally means "birth." And Sameach basically means "happy." Thus the literal translation is "happy birth festival" (celebrating the birth of Jesus Christ).

I don't know who answered the above, but Jews don't celebrate the birth of Jesus! See all the other answers for the correct meaning regarding the birth of the new moon each month.
First answer by Wellis68. Last edit by Fourskies. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 2 [recommend question].