You'd have to avoid the term "East," too, because it also has one of those suspect etymologies. Since the sun rises in the East, to know the date for Easter you would have to look East. Toward Ostara. That might seem like a far fetched explanation but the German for Easter is Ostern and the German for East is Osten.
So you could say "Happy Resurrection Sunday....um, SUNday?... uh-oh....
You'd also have to avoid the name of every single day of the week, since they are ALL named (originally) for Germanic gods and goddesses.
Wow. Such rationalization. Perhaps you can learn me about how coloring hard boiled eggs figures in the picture. We don't go around saying Happy Sunday as a way to refer to our appreciation for what Jesus did for us on that day.
Uh-oh. Did I burst your morally relativistic bubble?