I am aware that the names of the months are derived almost directly from the Babylonian calendar and that the Chumash itself never mentions a month by name and instead refers to it by number. Later on in Tanach (I believe only as early as Ezra and Nechemiah though I could be wrong) it starts to refer to months by name. I am also aware that the Mesopotamian new year began on the first day of the seventh month, called Tashritu and also on the first day of the first month called Nisannu. The Babylonian festival of Akitu is also eerily similar to Rosh Hashana and the Yamim Norayim in its themes and time placements. My question is twofold. Are there any sources relating to the taking of the months' names and maybe other religious practice developments of the time? And also, it seems very strange to me that we did not use names in our calendar until the first diaspora. Are there any theories as to why we did not have names in Chumash or what those names could be? It just seems strange to only have numbers for dates when no other culture does that.
Is it strange to have numbers for names of our months? Does no other culture do that?
Ummm....does September October November December...ring a bell? :)
In my observation of the human condition (maybe you will agree) I have seen that most people tend to like it when things are kept simple and Captain Obvious is in control. It is just natural for people to name things simply. Every town has a main street.
Regarding months of a year, cultures have usually used either numbers, agricultural ideas or events relating to that time of year, or gods/kings names, as names for months. Numbers are simply practical, farming/weather events are simple for people to remember, and beings seen as powerful, get respected. In short: math, food, religion!
Among the nations that use/used numbers as month names (besides Israel)are China, ancient Egypt, Japan, Thailand, and ancient Rome, to name a few. Egypt's civil calendar simply divided the year into 3 parts based on the Nile's activity and called each month in each set, #1-4.
Lets break down Rome's calendar, as it has different examples. At first, Rome had 10 months. March was the first (named after Mars, their god of war, because that's when armies could mobilize again after winter) then April (Aphrodite, another god) May (Maiah another god) June (Juno another god) then Quintillis (5 in Latin) Sextillis (6) September(7) October(8) November(9), and December(10). King Numa (c 700BCE) decided to add two months to the calendar to represent winter. Those 60 days would just be vacation without a name. So he named one month January (after his god of beginnings and ends) and another month February because the Roman purification holiday of Februa happened then. Julius Ceaser made some calendar reforms (The Julian Calendar) and decided to rename month #5 (boring name) to "July" because he thought that naming a month after himself, was way cool! Another emporer named Augustus, followed by changing month 6 to August ... after himself of course!
The joke is, that no one thought to change September - December from 7 - 10 into 9 - 12 since 700BCE!! That's dumb. But tradition dies hard. :)
So yes, we used numbers by Biblical decree. The agricultural names we did have, are hardly mentioned in Tanach, but we do have four names.
Aviv (spring, ripening, in Nissan; March-April) Exodus 13:4
Ziv (radiance, blossoming, in Iyar; April-May) I Kings, 6:1, and 6:37
Eitanim (strong ones, fruits are in their strength, in Tishrei; Sept-Oct) I Kings, 8:2
Bul (withering, in Cheshvan; Oct-Nov) I Kings, 6:38
It seems that our long exile over thousands of years has caused the other agricultural names to have been lost.
However, it is a Biblical commandment to constantly remember the Exodus from Egypt. See Devarim 16:3. "...in order that you should remember the day you went out of the land of Egypt all the days of your life."
By counting each month starting from the Exodus month as #1, we constantly remember the Exodus event throughout the year. (This is the 6th month ...6th since when, because? Oh right!)
The Ramban also explains this as the reason our days of the week only have numbers as names. There is a Torah commandment to "Remember the Sabbath day to keep it holy." Shemos 20:8. (Today is the 4th day...till the 7th = Shabbos!) So we will all remember the Sabbath is coming every day.
That should answer your second question.
As to your first question, part one:
The Talmud Yerushalmi (Rosh HaShannah 1:2) explains that when the exiles in Babylon came up to return to the land of Israel, they took the Babylonian months names with them. The Ramban sees this as a means to fulfill the verse in Jeremiah 16:14: "Therefore behold days are coming says Hashem, and it shall no longer be said as G-d lives, who brought up the children of Israel from the land of Egypt; rather, as G-d lives, who brought up the children of Israel form the north land (meaning Babylon)..."
Just as we needed to count months to remind us of the Exodus from Egypt, we also needed new month names to remind us of the Exodus from Babylon.
As to your question about "other religious practice developments.." :
Naming months and speaking Aramaic from Babylon, is not really a major religious adaptation. Jews were always Jews. Our religion is Judaism, and not Mithraism or Zoroastrianism etc. The Jewish religion has remained quite Jewish. :)
Your OP says: "The Babylonian festival of Akitu is also eerily similar to Rosh Hashana and the Yamim Norayim in its themes and time placements."
This is not a debate or lecture, so I will just point out one thing to help answer. Part of the Akitu festival, featured the king of Babylon reciting a "negative confession" before the priest of the god Marduk, in front of the people.
The confession is called negative, because the king in fact denies any wrong-doing. "I have not sinned O Lord of the universe, and I haven't neglected your heavenly might at all.."
Did Bill Clinton read the Akitu script before he told the press that he never inhaled? (Vladimir Putin drinks Vodka, but he never swallows)
Now take a look at a "Yomim Norayim" prayer book. Open to the "Al Chet" section. Jews make positive confessions to their G-d. We say "...we are not brazen faced and stiff necked to say before You that we are righteous and have not sinned, but rather we and our fathers have sinned!"
There is no similarity. A Babylonian claims he has not sinned, then asks his god for help etc. A Jew admits that he has sinned, and asks for G-d's mercy and help to do better.
I find the stark contrast to be quite "eery".
One religious innovation that we did bring up from Babylon was the Book of Esther, and the holiday of Purim!
On that note :)