Actually, three things.
Someone posts a dismissive reply to this type of thread without offering an un-debunked explanation of where the word "easter" comes form or how an egg-laying bunny has anything to do with Christ's resurrection.
(sigh)
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.