In case you want to say “Happy Thanksgiving” in Ancient Greek to any of your friends, here’s the way to do it.
Εὐτυχής ἡμέρα τῶν εὐχαριστιῶν
Εὐτυχής does not mean “happy,” but the expression εὐτυχής ἡμέρα τῶν εὐχαριστίων would be the equivalent phrase to “Happy Thanksgiving.” The adjective, εὐτυχής has an implication of success or good fortune.
Slight correction: in the gen. pl. the accent of first declension feminine nouns shifts to a circumflex over the ultima: εὐχαριστιῶν.
Of course you are correct, Grigoris. I’ve updated both the recording and the transcription to reflect the correction. Thank you for pointing out my mistake.