How do you say "Happy Anniversary" in Latin?

Question

I'm talking old Latin, not Spanish or anything modern.

Answer 1

Festus dies anniversarius.

But if you're going to wish it to someone, that would be in a different form, used as an object:

Festum diem anniversarium

Answer 2

feliz arniversario

i know because i speak old latin

if you want me to teach you some words

email me at [e-mail]

Answer 3

Anniversario Felice

Answer 4

Feliz anniversario

Answer 5

Dies fortunatus.

Earf!

P.S.  Thanks Notre Dame!