How do you say happy birthday in Celtic?

FYI: there is no single language called 'Celtic': it is a family of languages like 'Slavic'.Irish Gaelic: Breithlá sona duit. / Lá breithe shona duit.
Scottish Gaelic: Là breith sona dhuit (or dhuibh if formal).
Manx: Laa-ruggyree sonney dhyt.
Welsh: Pen-blwydd hapus.
Breton: Deiz ha bloaz laouen/ Kalz a vloavezhioù all.
Cornish: Penn-bloedh Lowen