What we know is that Jesus’s birth was actually before zero AD and most likely 4-6 BC. We know that Herod the Great died around 2-4 BC, and Jesus was already born before that date.
Personally, I believe Jesus was born on the 1st of Abib (also known as Nisan) in 4 BC. The reason I believe this is based on two key verses in the Bible:
Exo 40:2 “Set up the tabernacle, the Tent of Meeting, on the first day of the first month.
It took around 9 months to build the Tabernacle after they got the plans on how to build the Tabernacle from God during the Feast of Pentecost (Feast of Weeks kind of the conception of the Tabernacle)
Joh 1:14 And the Word became flesh, and did tabernacle among us, and we beheld his glory, glory as of an only begotten of a father, full of grace and truth.
The Holy Spirit of God came over Mary to conceive Jesus (Luk 1:35). I believe this also happened during the period of Pentecost, matching that of the Tabernacle.
Another reason is that all feasts and things that happened to Israel were shadows of things to come.
- 10 Abib: Shabbat HaGadol – Inspecting the Passover Lamb (Exo 12:3)
- 14 Abib: Passover – Jesus sacrificed as the Passover Lamb (1Co 5:7)
- 18 Abib: Jesus presents Himself as First-Fruits to the Father (Joh 20:17)
- Pentecost: Was the time Old Covenant with Israel was made and the day God gave the Holy Spirit to the Disciples, which is key in the New Covenant
- Spring Feasts: First Coming of Christ
- Fall Feasts: Second Coming of Christ
So as we can see that the shadow of things to come are in a logical sequence which indicates Jesus’s birth should take place before the 10th of Abib. The First of Abib is the new beginning (real new year), the day the Tabernacle got initiated, and God dwelt among men again.