It's nice that you want to say something. I don't fast for medical reasons but I still say thank you when someone wishes me an easy fast. It just means they are thinking of me on the holiday. People still say happy new year on YK. People were saying it to each other at Temple yesterday so it's fine. No one will be offended if you say happy new year or have an easy fast. Yes, on YK we are atoning for our sins and asking to be inscribed in the book of life for the coming year but I would think it odd if one of my non-Jewish friends used the Hebrew expression for inscription in the book of life to me -- but that's just me. It's nice that you're sensitive to the fact that this is our holiest time of the year and want to acknowledge it. Thank you!

Not everyone fasts on YK - it's a long story. Saying "have an easy fast," is kind of tricky, therefore.

The new year begins on Rosh Hashanah, when you get "inscribed in the book of life," but YK is when you get "sealed," if you are lucky. Listen to Leonard Cohen's "Who By Fire," which was inspired by a YK prayer.

Therefore, Shana Tova - a good year - is an appropriate sentiment for YK as well, or you can say, "G'mar Hatima Tova," which translates to "may you be inscribed in the book of life."

Have a good day!