Rosh Hashanah or Yom Teruah / the Day of Blowing Shofar
This is the first Fall Festival that the Sages assigned it as the New Year, hence the Name Rosh Hashana, from the tradition that this is the day when Adam was created; the completion of the whole creation of the world.
The main theme of this Festival is the regathering of dispersed of Israel from the 4 corners of the earth (Isaiah 11:11 -12; Thessalonians 4:16-18; Matthew 24:31 He will send His angels with a great sound of a trumpet, and they will gather together His elect from the four winds, from one end of heaven to the other). It is for this reasons Shofar is blown in the Synagogues. This points to the time when The Bride-groom; The King Messiah; the Son of David will be coming to take His Bride for Himself. 
It is time to take the step of reconciling with others, and returning to GOD in repentance, and rededicating our lives to the LORD, pleading allegiance to His everlasting covenant with the Fathers – Abraham, Isaac and Jacob.