`happy birthday`: English to Latin.
Results
happy birthday (phrase) [informal, idiomatic, polite]
expression wishing joy on birthday
felicem diem natalem [informal, idiomatic, polite]
Happy birthday, my friend! — Felicem diem natalem, amice!
felix natalis dies [informal, idiomatic, polite, poetic]
Happy birthday, Julia! — Felix natalis dies, Iulia!