Exodus 12: 1 ADONAI spoke to Moshe and Aharon in the land of Egypt; he said, 2 "You are to begin your calendar with this month; it will be the first month of the year for you.
In Exodus 12:1-2, Yahweh tells Moshe that the year from then on will begin "this month", but it is not for the purpose of counting years; rather, it is in commemoration of the momentous transformation, from slavery to physical liberation from Egypt.
Passover, on the other hand (which many call the beginning of the New Year) is celebrated in its own right as the pivotal event which led to the Exodus. Therefore, the 1st day of Nisan became the date for the first month of the Hebrew/Jewish calendar.
In other words, months in the Hebrew/Jewish calendar are numbered beginning with the month of Nisan as explicitly stated in the Torah. In fact, the title "First of the Months" ("Rosh Hodashim" in Hebrew) is reserved in the Torah for the month of Nisan (Exodus 12:2).
Then there is also the "civil year", the point in the year from which the years are counted. This is the historical date agreed upon by the sages that was the date of the creation of man. Yom Teruah/Rosh Hashana (in September 2010), kicked off the year 5771 from the creation of Adam.
Counting years from Tishri (Yom Teruah/Rosh Hashana) is also the date for calculating the release year (i.e., the "Sh'mittah" year, which means "Sabbatical" year, which is every 7th year in the 49-year cycle that governed the Kingdom of Israel [10th century B.C.E. to 8th century B.C.E.] and Kingdom of Judah [10th century B.C.E. to 6th century B.C.E.] in biblical times), and the date for calculating the Jubilee year (a Jubilee year or "Yovel" year in Hebrew is the year after the 49-year cycle that governed the Kingdom of Israel and Kingdom of Judah in biblical times, i.e., the 50th year).
The 1st day of Tishri was also the date that determined the beginning of the year when it came to the three years that the fruit of a tree must be left unpicked (Leviticus 19:23). The 1st day of Tishri was also the date for the "tithe of crops" for the Levites and the Priesthood ("Cohanim" in Hebrew), whose dedication to holy service prevented them from working on the land like the other Hebrews.
Though the month of Tishri is the beginning of the "New Year"; that is, you increment the year count and observe other events, it is counted as the "7th Month" because Yahweh commanded that the months be counted from Nisan. We see that Tishri is counted as the 7th month in Leviticus 23:24, and in 1 Kings 8:2. (Don't get caught up in the names of the months. In Biblical times, what we call today "Nisan" was then "Aviv", and what we call today "Tishri", in Biblical times was "Etanim".)
We see, too, that Tishri is also considered the "beginning of the year" in Ezekiel 40:1, which clearly refers to Yom Kippur (tenth day of the month); yet Ezekiel refers to the month as the beginning of the year (as it is Tishri). So one must simply be savvy on what count or calendar the author is referring to when reading the Bible! Today it causes us great trouble, but in the age in which these things were written, everyone clearly understood!
Let's examine how we know Ezekiel 40:1 is referring to Yom Kippur!
"In the twenty-fifth year of our exile, at the beginning of the year, on the tenth day of the month - this was the fourteenth year after the city [of Yerushalayim] was struck - it was on that very day that the hand of ADONAI was on me, and he took me there."
Note the date: "...beginning of the year, 10th day of the month".
Though YHWH said, at the beginning of the Exodus, in Exodus 12:2, that "You are to begin your calendar with this month; it will be the first month of the year for you" - this means that the Hebrews already had another "1st month"! If this were not true, Exodus 12:2 would not make sense!
So now, look at Exodus 34:22 "Observe the festival of Shavu'ot with the first-gathered produce of the wheat harvest, and the festival of ingathering at the turn of the year." - with emphasis on the last phrase: "...and the festival of ingathering at the turn of the year."
This "festival at the turn of the year" is AFTER Shavuot. But this festival which follows Shavuot is one of the 3 times a year the men are to appear before YHWH - Lev 23 verse 2: "2 Tell the people of Isra'el: 'The designated times of ADONAI which you are to proclaim as holy convocations are my designated times.'"
So let's look at the three times the men are to appear before YHWH:
1. Leviticus 23: "5 In the first month, on the fourteenth day of the month, between sundown and complete darkness, comes Pesach for ADONAI. 6 On the fifteenth day of the same month is the festival of matzah; for seven days you are to eat matzah. 7 On the first day you are to have a holy convocation; don't do any kind of ordinary work. 8 Bring an offering made by fire to ADONAI for seven days."
(So, Pesach is number 1).
2. Leviticus 23: "16 until the day after the seventh week; you are to count fifty days; and then you are to present a new grain offering to ADONAI. 17 You must bring bread from your homes for waving-two loaves made with one gallon of fine flour, baked with leaven -as firstfruits for ADONAI."
(So Shavuot is number 2).
3. Leviticus 23: "24 Tell the people of Isra'el, 'In the seventh month, the first of the month is to be for you a day of complete rest for remembering, a holy convocation announced with blasts on the shofar. 25 Do not do any kind of ordinary work, and bring an offering made by fire to ADONAI." (And this "bring an offering" gathering is also tied to the 15th of the month - Sukkot - as we see in Leviticus 23:34-35, and 2 Chronicles 8:13.)
(So Yom Teruah, 1 Tishri, the 7th Month, and Sukkot is the 3rd time all men are to appear before YHWH).
But the "Calendar begins with Nisan" per Exodus 12:2, while "Tishri is the 7th month" per Lev 23:24!
But Tishri is also "The turn of the year" per Exo 34:22. Ahha! Tishri was the original start of the year that YHWH changed in Exodus 12:2!
There you have it! Years are counted at the "turn of the year" by Tishri, even though after the Exodus, Tishri became the "7th month", yet the "Year begins with Nisan" since YHWH said so when the Exodus began! Thus there are "two years" in the Hebrew calendar - the Spiritual year which begins in Nisan, and the "civil" year, which continues to be counted from Tishri.
Thus, we now see that in Ezekiel 40:1, when it says "...at the beginning of the year, on the tenth day of the month", we understand that it is the month of Tishri (the "turn" of the year"), and the 10th day therefore is Yom Kippur!
Thus the Jewish calendar has forever counted the HOLY year from the Exodus, but counts the "turn of the year" from 1 Tishri. So, the easiest for us to understand is that months are counted from Nisan in remembrance of the Exodus, but years are counted from Tishri, along with a host of other record-keeping events.
- The spiritual year, or sacred year starts with Nisan.
- The civil year or "civil calendar" is determined from Tishri.