Why do we celebrate Tu B’Shevat? Unlike other holidays, it is neither mentioned in the Torah, nor does it commemorate a historic event. What exactly are we celebrating?

The Mishnah1 explains that there are four heads of the year, four dates on the calendar when the yearly cycle begins anew for specific purposes:2

The first of Nissan is the new year for kings and for festivals. In the olden days, documents were often dated counting from the reign of the monarch. Now, when does the first year end and the second one begin? It would have been highly inconvenient to use the actual anniversary of his coronation, since not everyone knew the date, and every king had a different date of ascension. Thus, the first day of Nissan served as that day. No matter when a king was crowned, his first year ended and his second year began on that day.

The first of Elul is the new year for the cattle tithe, but according to Rabbi Eliezer and Rabbi Simeon, it is on the first of Tishrei. A Jewish farmer is obligated to tithe his livestock, consecrating every tenth animal. But all ten animals counted must be born in the same year. So when does one group end and another one begin? The first of Elul (or according to some, on the first of Tishrei).

The first of Tishrei is the new year for years, for Sabbatical years and Jubilees, and for the planting of trees and herbs. This is our beloved Jewish New Year, Rosh Hashanah, which we celebrate by hearing the shofar, praying, and feasting on sweet foods.

The first day of Shevat is the new year for trees, according to the school of Shammai, but the school of Hillel says it is on the fifteenth of the same month. Like cattle, 10% of our fruit must be tithed, and we must not tithe fruit from one year together with fruit of another. So when does one arboreal year end and another begin? The halachah follows the school of Hillel, which teaches that it was on 15 Shevat (Tu B’Shevat).

Rabbi Levi Yitzchak Schneerson shares several teachings regarding the yearly cycle and its various heads:

Three or four heads?

The Mishnah states that there are four heads of the year. Yet, according to Rabbi Eliezer and Rabbi Simeon there are only three (since they combine the first of Elul with Tishrei). Rabbi Levi Yitzchak points out that this ambiguity is reflected in the letter shin, which is linguistically similar to the Hebrew word for “year,” “shanah. While we are most familiar with the shin with three heads, it sometimes appears with a fourth head. For example, the tefillin we wear on our heads has a three-headed shin on one side, and a four-headed shin on the other—appropriately reflecting the shanah, which has either three or four heads.

Twelve or thirteen months?

Jewish years are not all the same length. Most have 12 months. But every few years, there is a “leap year” with a 13th month that helps us keep the lunar and solar cycles in sync. This same elasticity is seen in the 12 Tribes of Israel, which come from the 12 sons of Jacob. At first glance, there seem to be only 12 tribes. But in fact, Jacob split the tribe of Joseph into two, when he “upgraded” his grandsons, Ephraim and Manasseh, to be like sons to him. This brings the count up to 13. But then we have the Tribe of Levi, which was not granted any land in Israel, which is often seen as a separate entity, not counted among the tribes, bringing the count down to 12 again. Thus, the Tribes of Israel are both 12 and 13—just like the months of the year.

This is seen on a deep mystical level as well. The year is connected to the letter vav of G‑d’s ineffable name (the explanation for this connection is beyond the scope of this article). Now, the letter vav is often spelled out as וו, which has the numerical value of 12 (6+6). But other times, it is written as ואו, which has the value of 13 (6+1+6).

Scripture at Age Five

The sages instituted that five years of age is the appropriate time to begin learning Scripture. At that point, a child may have mastered the Hebrew letters and vowels and is ready to read the Torah. The Hebrew word for “year,” “shanah” (שנה), has the numerical value of 355 (which is exactly how many days some Hebrew years have). After five years, a child acquires a total of 1,775 (355x5). Now take the letters of the alphabet, and add up their numerical value—with aleph worth 1, bet worth 2, all the way to tav being worth 400—and you will arrive at a grand total of 1,775.

What, you tried it, and you only arrived at 1,495? Of course, you also need to add in the value of the five final letters, and you will arrive at the right number.

Tu B’Shevat Insights

Back to the new year of the trees. While there is disagreement with regards to the date, all agree that this event takes place in the month of Shevat. Rabbi Levi Yitzchak writes that the word “Shevat” (שבט) has exactly the same numerical value as “ilan” (אילן), the Hebrew word for “tree.”

How can that be? Shevat adds up to 311 (300+9+2), and ilan only reaches 91 (1+10+30+50)!

The solution is to let the tree spread its branches a bit. Take every letter and spell it out in full:

Letter Full Spelling Full Value
א אלף 111
י יוד 20
ל למד 74
ן נון 106

Now add up 111+20+74+106, and you arrive at 311, exactly the same value as the month of Shevat.


Igrot Kodesh p. 414.

Torat Levi Yitzchak p. 366.

Rabbi Levi Yitzchak’s personal diary.

Igrot Kodesh p. 413.