When is Vocaloid Tetos birthday?

teto was relased in april 1 st as a ''new member of Vocaloid'' it was in aprilfools day i think it was some kind of joke for vocaloid fans ''oh look a new vocaloid'' she is actually utauloid. But i have no idea if teto's birthday is at 1.4 or 9.4 I'M NOT SURE!