There are two calendars in operation in the scri ptures; will relate to the coming of Messiah
Q. Why do some people say Rosh Ha Shanah is the head of the year and some say the head of the year is really in the spring.
A. The term Rosh Ha Shanah means "head of the year" but it is not the Biblical name for the festival.
The name for the festival on Tishri 1 should be called "Yom Teruah" which means the "day of the awakening blast (teruah) of the shofar.
It can be found in Num. 29.1.
You will see it in Hebrew and it is translated in English as a "day of the blowing of trumpets."
The confusion you speak of comes from a basic misunderstanding of the scri ptures, which I will try to explain briefly but much more can be said.
In Genesis 1 God creates the heavens and the earth.
The first day of creation is seen by many to be Tishri 1, day 2 Tishri 2 and so on.
Others see Tishri 1 beginning on day four when He created the moon, but no matter which way you look at it, time began that first week of creation.
This is referred to as the civil year and the dates given up to Exodus 12 are according to the civil calendar.
That’s how you figure the years.
So, each Tishri 1 is called a rosh (head) shanah (year) or "new year."
In Exodus 12.2 God says this (new moon) shall be the beginning of months for you and He is referring to a religious calendar He is going to institute.
The religious year begins on Aviv (Nisan) 1 with the new moon for that month.
Every date given in the Bible after that will be according to the religious calendar.
So, there are two calendars operating at the same time in the Bible, one civil and one religious.
The civil year begins in Tishri in the fall and the religious year begins in Aviv (Nisan)in the spring.
In Exodus 23.14-17 we see the Lord commanded Israel to appear before Him three times a year.
In V 16 He says the Feast of Ingathering (Sukkot) will happen at the "turning of the year" and He is talking about the civil year in the fall.
We know He said Aviv (Nisan) is the beginning of the religious calendar, but here he says there is another new year in the fall, which is the civil year beginning on Tishri 1.
He says the same thing in Exo. 34.22 and Deut 14.28 so there is no mistake about it.
We will see the two calendars in action again in Joel 2.23 where the Lord says He will send the early and Latter rain "as in the first month."
Now, you can’t have the rains in the spring and the fall happen "in the first month" unless there are two calendars.
These two calendars will directly relate to the coming of the Messiah.
When you look up the Hebrew terms for early and latter rains you will find that is says "moray Tzedekah" which means "teacher of righteousness."
So, He says the teacher of righteousness (Yeshua) will come upon Israel in the spring and fall, during the religious and civil new years.
When you check the dates given from Genesis 1.1 to Exodus 11.10 they will be according to the civil calendar.
Every date given after Exodus 12.1 will be according to a religious calendar.
So, those are some examples of two calendars operating together in the Bible.
How does this concept relate to prophecy.
Yeshua appears during the spring festivals, is crucified, buried and resurrected all on the first three festivals in the religious first month of Aviv (Nisan).
He sends the Holy Spirit at Shavuot (Pentecost), but that is not in Aviv but it is the concluding festival of the spring season.
He will also come the second time during the fall festivals that happen during Yom Teruah (rosh ha shanah), Yom Kippur and Sukkot, at the "turning of the year" according to the civil calendar.
So, to understand eschatology and prophecy one has to know that there are two calendars in operation in the scri ptures.
The confusion comes in when people don’t understand that and take Exodus 12 to mean the civil year when it is only referring to a religious calendar that the Lord is instituting, not meaning to replace the civil one, but to operate along side of it.