Why do we celebrate the new year at Rosh Hashanah?

Yesterday we ended with the question of where we got the name Rosh Hashanah [lit. "head of the year"] for the first day of the seventh month. Why do we observe the new year celebration in the middle of the year, on Rosh Hashanah?

The answer was alluded to in one of the footnotes from yesterday's post:

There were two celebrations of a new annual cycle in ancient Israel, one in the spring month of Aviv (later called Nisan), 'the first of the months of the year' (Exod. 12:2), and another in the fall at 'the turn of the year' (Exod. 23:16, 34:22)." (Entering the High Holy Days, p. 4)

Did you catch that? In ancient Israel, there were actually multiple new years!

While this may at first seem strange, it actually is not. Here in the United States, we also have multiple new years: on January 1 we celebrate the turning of the year, while the government (and many corporations) have a fiscal year for accounting purposes. And schools start a new year each September!

Similarly,

In Judaism, Nissan 1 is the new year for the purpose of counting the reign of kings and months on the calendar, Elul 1 (in August) is the new year for the tithing of animals, Shevat 15 (in February) is the new year for trees (determining when first fruits can be eaten, etc.), and Tishri 1 (Rosh Hashanah) is the new year for years (when we increase the year number. Sabbatical and Jubilee years begin at this time). (http://www.jewfaq.org/holiday2.htm)

Thus, in the mishnah* we find:

The first of Tishre is the beginning of the year [Rosh Hashanah] for years, sabbatical cycles, and the jubilee. (M. Rosh Hashanah 1:1)

Similar to New Year's Day in the United States, Rosh Hashanah is the time in the Jewish calendar when the year number increases. But while in the U.S., the year increases on the first day of the first month, in the Jewish calendar, the year increases on the first day of the seventh month--at the "head" or "turn" of the year! Thus, it's become the custom to wish each other 'L'shana Tova!' (literally "To a good year!") at Rosh Hashanah, and to eat apples and honey in hope for a sweet year.

If this was new to you, let me know in the comments section below!

* The mishnah is the earliest written codification of Jewish oral traditions (compiled c. 200CE by Judah haNasi). It contains the details of how the people of Israel kept the commandments of the Torah in practice. The mishnah is the core around which the Talmud is organized.