See the names of the months and their position according to the biblical pre- and post-Babylonian era with the sequence reflected according to scripture and not the secular construct.
Feast of Weeks
First/Third month Nisan (Abib)/Sivan
April 22 thru June 10 (at evening, April 21 until evening, June 9)
June 10 (at evening, June 9 a righteous convocation)
An Israelite festival (also called Pentecost: Greek; feast of harvest; day of firstfruits) celebrated seven weeks after the feast of unleavened bread, or fifty days (the period between the barley harvest to the wheat harvest). It is a feast of thanksgiving for the completion of the harvest season.
Memorial of Blowing of Trumpets
The seventh month Tishri (Ethanim)
October 1 (at evening, September 30 a righteous convocation)
Also called feast of trumpets. The sounding of the trumpets (shophar; shofar; ram’s horn) is used to call the congregation of Israel to gather together. The instrument was blown to signal an announcement or alarm during times of peace and war, such as, the Jubilee Year (Lev. 25:8-13), Sabbaths, and the fall of the city of Jerico (Jos. 9).
Day of Atonement
Seventh month Tishri (Ethanim)
October 10 (at evening, October 9 until evening, October 10)
October 10 (at evening, October 9 a righteous convocation)
An annual fast day of the Israelites. Ordained by YHWH in the torah instructions as a day to humble oneself and repentance of transgressions. A person abstains from food and drink from evening til evening.
Atonement for idolatry and disobedience against YHWH spans both Testaments, pointing to the substitutionary sacrifice of animals and then ultimately YHWH the Son offering his body in place of the wrath of YHWH.
Feast of Tabernacles
Seventh month Tishri (Ethanim)
October 15 thru October 21 (at evening, October 14 until evening, October 20)
October 15 (at evening, October 14, a righteous convocation)
October 22 (at evening, October 21, a righteous convocation)
An Israelite festival (also called Feast of Booths; Feast of Ingathering) held at the end of the autumn harvest. It celebrates a renewal of the covenant after YHWH liberated the children of Israel from their captivity in Egypt (Mizraim; land of bondage) through words and plagues delivered by Moses and recalls wandering in the wilderness forty years, dwelling in booths (tabernacles), until the rebellious against YHWH were destroyed.
Feast of Dedication
Ninth month Kislev (Chislev, Casleu)
December 25 thru January 1 (at evening, December 24 until evening, December 31) December 25 (at evening, December 24, a righteous convocation) January 1 (at evening, December 31, a righteous convocation)
An eight day Israelite festival (also called Feast of Lights; Hanukkah; Chanukah) observing the victories of Judas Maccabbeus (the southern kingdom; Judah) who lead the battle against Idumea (Esau) and the purification and rededication of the temple after Antiochus Epiphanes profaned the temple with paganism.