Praying the evening prayer (Maariv, or Arvit) before the obligatory time:
lf a Shaliach lives in a place where the minyan (prayer quorum of at least ten men)for Maariv takes place before tzeit hakochavim, (the appearance of stars in the sky) should
he pray with the minyan, or by himself after tzeit hakochavim?
Answer: If he prayed Mincha that day within an (halachic) hour and a quarter before sunset, he may pray Maariv before the appearance of stars, and after that he should recite the Shma prayer again. During the period of Sefirat HaOmer, he should recite that also after the tzeit hakochavim. (Tzeit hakochavim as in the halachically defined time in special calendars.)