All who are born generally have a birthday celebration: mostly by parents and their friends and relatives around the birth; later by the person him/herself with his friends and relatives each year on the date.
One who has become born-again from Above as a believer in Yeshua/Jesus celebrates his/her new birth as a child of God, and remembers this yearly, even daily.
Israel/the Jewish people celebrates her birth as a nation at the Passover each year, when YHVH God redeemed and delivered them as a people from Egypt and hard bondage.
The Fall “Feasts of the LORD” — beginning with the Memorial of [Trumpet] Blasts, through the Day of Atonement and the Feast of Booths/Tabernacles — look ahead to the new birth of the nation as the Israel of God, when their sins are forgiven under the New Covenant.
Double birthdays; double New Years. Save your people, O LORD, God of Israel! May many more Jewish people come to know Yeshua/Jesus as their Savior and Lord during this coming year. It is better to know Him “today” and be found in Christ/Messiah, than to wait uncertainly if any might be shown mercy and included in His salvation of “all Israel” in that Day.