Rosh Hashanah (Feast of Trumpets) occurs every year on Tishri 1, the first day of the first month of the Hebrew civil year. Hebrew (Biblical) calendar rules determine when Tishri 1 is declared. Once it is declared then the remaining six feast (holy) periods fall into place. Dates for Rosh Hashanah can be viewed in our article on dates for God's annual Feast Days.
Old Testament meaning
Jewish tradition places the giving of life to Adam and Eve on a Friday afternoon on September 26, 3760 B.C. This event was just hours before the start of the weekly Saturday Sabbath, which would also begin Tishri 1 (Rosh Hashanah) and the first feast day kept by humans.
The meaning of this day seems to be derived from the fact that trumpets were used as alarms to warn people of an impending important event like war (Jeremiah 4:19, Ezekiel 7:14 and chapter 33, Joel 2:1). They were also used to announce the coronation of Israel's new king (1Kings 1:33 - 39, 2Kings 9:13, 11:14, 2Samuel 15:10).
The only recorded observance of Rosh Hashanah, outside its mention in the Pentateuch, is in a parallel account found in Ezra and Nehemiah. On the first day of the seventh month (Tishri is the seventh month of the sacred, not civil, year), the prophet Ezra began to read God's law to those who had returned to Israel from Babylonian captivity (Nehemiah 7:73 - 8:12). His words moved the people to repent (8:9 - 11) and then later to keep the Feast of Tabernacles (Ezra 3:1 - 4, Nehemiah 8:14 - 18).
New Testament importance
Jesus' birth took place between August 27 and September 9 in 5 B.C. (Hebrew year 3757). Given that Jesus was born a king (Matthew 2:2, Revelation 17:14, 19:16) and a trumpet will herald war against Satan during his Second Coming, his birth almost certainly occurred on Rosh Hashanah. This would mean he was born on Saturday, September 2, in 5 B.C.
Several Biblical passages show that Rosh Hashanah symbolizes the wrath of God and the future return of Jesus Christ to the earth (Joel 2:1; Zephaniah 1:14 - 18, etc.).
The prophetic Day of the Lord, when God actively intervenes in world affairs to punish those who worship the Beast power, starts with the sounding of a trumpet (Revelation 8:1 - 7). Seven trumpets total will be blown by angels, signaling various actions taken by the Eternal (Revelation 8 - 9, 11:15).
The final seventh trumpet announces that the time has arrived for God's kingdom to come to the earth and rule over mankind (Revelation 11:15). Jesus begins his return (19:11 - 21) after further punishments are delivered on the unrepentant (chapters 15 - 16, 17:14).
Rosh Hashanah, however, symbolizes far more than the perfect defeat of Satan the Devil (Revelation 18) through the return of Christ. It also heralds the first resurrection of the dead, when all those who died in faith will be made immortal and rule with the Lord during the Millennium (1Corinthians 15:52, 1Thessalonians 4:16, Revelation 20:4 - 6).
A day worth keeping
Rosh Hashanah was for ancient Israel, and still is for New Testament Christians, a commanded day of rest where believers gather in a sacred assembly to worship God. This day's rich symbolism heralds the start of the fall festival season that ultimately ends with the joyous keeping of the Feast of Tabernacles (Feast of Booths) and the Last Great Day.