What is the HALACHA when the father heard in one day and the fiance heard in another day? for each of them it's "YOM SHOM'O"? so, they can't "le'hafer" together?
SHANA TOVA AND GMAR CHATIMA TOVA
Most Rishonim rule that each is Mefir during the day that they hear. They are not dependent on each other. (Ramban 68a)
However, the RAMBAM (Nedarim 12:17) infers from the verses of Hafaras Nedarim that they must both be Mefir on the same day, the day on which the first of them heard. (The Vilna Gaon finds some support for this from a Sifri.)