I am Ashkenazi and frequently attend a Sephardi minyan for Maariv. It seems like many Sephardim consider Tzeit HaCochavim to be much earlier than Ashkenazim. Can one rely on this and daven with their minyan? If so, must I repeat Kriat Shema again or I am yotzei?
It is best for you not to daven with this minyan, but if there is no choice than daven with them and after Tzeit Hakochavim you should repeat Kriyat Shema (all 3 Parshiyot). Rabbi Yitzchak Grinblat