From 2 to Ziv to Iyar: Why We Have Babylonian Names for Jewish Months

(4) You go free on this day, in the month of Abib.

(2) Israel’s entire delegation gathered before King Solomon at the Feast [of Booths], in the month of Ethanim—that is, the seventh month.

(1) In the month Eisonim. [Targum] Yonoson rendered, “In the month which people of the ancient times called the first month, on the festival, and at present it is the seventh month,” i.e., since the Torah was given, and it is written in the month of Nissan which it is the first of the months, [therefore,] Tishrei Although the construction of the Beis Hamikdosh was completed in the eighth month of the previous year [see above 6:38], Shlomo postponed its dedication until the following Tishrei. is called the seventh [month].איתן means “mighty” and ירח האיתנים refers to the month of Tishrei which has the strongest spiritual effect for people to improve themselves because of the holidays celebrated during Tishrei—Ralbag. Alternatively, איתנים alludes to the Patriarchs. See Maseches Rosh Hashana 11a.

(1) In the month of Bul. This is [the month of] Mar CheshvanThe Flood [מבול] during Noach’s time began in the month of Marcheshvan. [when] the grass in the field decays, and cattle is given fodder from what is stored, from the expression “and he gave fodder [ויבל] to the donkeys.”

(9) So the king’s scribes were summoned at that time, on the twenty-third day of the third month, that is, the month of Sivan; and letters were written, at Mordecai’s dictation...

(1) The narrative of Nehemiah son of Hacaliah:
In the month of Kislev of the twentieth year, when I was in the fortress of Shushan,

MISHNAH: On the first of Tishre is New Year for years, and remission of debts, and Jubilee periods, and for planting, and vegetables... On the first of Shevaṭ is New Year for trees...following the House of Shammai; the House of Hillel say, on the fifteenth of it. HALAKHAH:...He said to them, from here on you are quarrelling with me about names of months? As Rebbi Ḥanina said, the names of the months ascended with them from Babylonia.

(1) THIS MONTH SHALL BE UNTO YOU THE BEGINNING OF MONTHS. This is the first commandment which the Holy One, blessed be He, commanded Israel through Moses. Therefore it says here [that the Eternal spoke unto Moses and Aaron] in the land of Egypt. for the rest of the commandments of the Torah were given to him on Mount Sinai... Now the purport of the expression, This month shall be unto you the beginning of months, is that Israel is to count this as the first of the months, and from it they are to count all months — second, third, etc., until a year of twelve months is completed — in order that there be through this enumeration a remembrance of the great miracle, [i.e., the exodus from Egypt, which occurred in the first month]. Whenever we will mention the months, the miracle will be remembered. Thus everytime a person says, for example, “the third month,” he implies that it is the third in the order of the months which begins with Nisan, when the exodus occurred. It is for this reason that the months have no individual names in the Torah. Instead, Scripture says: In the third month; Further, 19:1. And it came to pass in the second year, in the second month … that the cloud was taken up from over the Tabernacle of the Testimony; Numbers 10:11. And in the seventh month, on the first day of the month, etc. Ibid., 29:1. and so in all cases. Just as in counting the weekdays we always remember the Sabbath-day since the weekdays have no specific name of their own, but instead are called “one day in the Sabbath,” “the second day in the Sabbath,” as I will explain... so we remember the exodus from Egypt in our counting “the first month,” “the second month,” “the third month,” etc., to our redemption.
This order of the counting of the months is not in regard to the years, for the beginning of our years is from Tishri, [the seventh month], as it is written, And the feast of ingathering at the turn of the year, Ibid., 34:22. Now the feast of ingathering is in the seventh month (Leviticus 23:39) and yet Scripture calls it here at the turn of the year, which means the beginning of the new year. Thus we learn that Tishri is the beginning of the year, although in the order of the counting of the months it is the seventh month. and it is further written, And the feast of ingathering, at the end of the year. 23:16. If so, when we call the month of Nisan the first of the months and Tishri the seventh, the meaning thereof is “the first [month] to the redemption” and “the seventh month” thereto. This then is the intent of the expression, it shall be the first month to you, meaning that it is not the first in regard to the year but it is the first “to you,” i.e., that it be called “the first” for the purpose of remembering our redemption.
Our Rabbis have already mentioned this matter when saying, Yerushalmi Rosh Hashanah I, 2. “The names of the months came up with us from Babylon,” since at first we had no names for the months. The reason for this [adoption of the names of the months when our ancestors returned from Babylon to build the Second Temple], was that at first their reckoning was a memorial to the exodus from Egypt, but when we came up from Babylon, and the words of Scripture were fulfilled — And it shall no more be said: As the Eternal liveth, that brought up the children of Israel out of the land of Egypt, but: As the Eternal liveth that brought up and that led the children of Israel from the land of the north Jeremiah 16:14-15. The expression and that led is found ibid., 23:8. — from then on we began to call the months by the names they were called in the land of Babylon. We are thus reminded that there we stayed [during our exile] and from there, blessed G-d brought us up [to our Land].From Ramban’s “Sermon on Rosh Hashanah,” where he discussed the same topic (Kithvei Haramban, Vol. I, p. 215), it is crystal clear that the author’s intent here was not that the memorial of the redemption from Babylon will thrust aside the memorial of the redemption from Egypt. Rather, the one of Babylon will be added to that of Egypt, so that the names of the months will be reminiscent of the two redemptions together. See Note 114 further, for example. Joseph Albo’s position in his book Ikkarim (Roots) that Ramban’s intent here was that after the return from the Babylonian exile, the first memorial was to give way altogether to the second, is thus not correct. For further discussion of this problem see the note in my Hebrew commentary Vol. II, p. 520. These names — Nisan, Iyar, and the others — are Persian names and are to be found only in the books of the prophets of the Babylonian era See Zechariah 1:7, etc.; Ezra 6:15; Nehemiah 1:1. and in the Scroll of Esther Esther 3:7, etc. It is for this reason that Scripture says, In the first month, which is the month of Nisan, Ibid. Thus both memorials are mentioned simultaneously: the first month to our redemption from Egypt, which is the month of Nisan, a name which is reminiscent of our Babylonian exile from which we have also been redeemed. just as it says, they cast ‘pur,’ that is, the lot. Ibid. In this case too Scripture explains the Persian word pur as meaning lot, just as it explained the name Nisan as being “the first month.” To this day, people of Persia and Media use these names of the months — Nisan, Tishri, and the others — as we do. Thus through the names of the months we remember our second redemption even as we had done until then with regard to the first one.