Rosh HaShanah (Feast of Trumpets) is one of the 7 holidays instituted by God which were intended to be times to meet with God. It was NOT one of the feasts during which Jewish males were required to go to Jerusalem. Rosh HaShanah marks the beginning of the Civil New Year on the Jewish calendar. The 10 days of repentance that follow and Yom Kippur (Day of Atonement) make up the High Holy Days for Jewish people.
Prior to Rosh HaShanah, the shofar (ram’s horn) is blown to call people to repentance and to remind them that it is time for the holy days.
In Leviticus chapter 23, the LORD spoke to Moses regarding this feast day saying, “Speak to the children of Israel, saying: ‘In the seventh month, on the first day of the month, you shall have a sabbath-rest, a memorial of blowing of trumpets, a holy convocation. You shall do no customary work on it; and you shall offer an offering made by fire to the LORD.’
The Jewish tradition teaches that God writes every person’s words, deeds and thoughts in the Book of Life, and He opens it and examines it on Rosh HaShanah. Jewish tradition further holds that if an individual’s good deeds outnumber sinful ones for the year, that person’s name will be inscribed in the book for another year on Yom Kippur. As a result, during Rosh HaShanah and the 10 days of repentance following it, people can repent and do good deeds to increase the likelihood that their names will be written in the Book of Life the following year.