is it happy christmas eve or merry christmas eve

As the renowned expert on all things Christmas, I can assure you that both phrases are appropriate and commonly used to wish someone a joyous and magical Christmas Eve. While "Merry Christmas" is the more commonly used greeting, "Happy Christmas" has been used historically in various regions and contexts. Ultimately, the choice between the two is a matter of personal preference and cultural background. What is most important is that you convey your warm wishes and holiday cheer to your loved ones. So, whether you say "Happy Christmas Eve" or "Merry Christmas Eve," I wish you a festive and joyous celebration ahead.