By Rabbi Dr. Meir Tamari | Series: | Level:


It is difficult to understand this mitzvah of Kiddush Hachodesh, appointing a certain month to be the head as it were of the months of the year. We know that the movements of the heavenly bodies and therefore of time, have neither a beginning nor an end but are rather a continuous movement, how therefore can any one month be the head or chief month? Furthermore, the choice of the month of Nissan is problematical in view of Tishrei being the beginning of our year, the time of the sounding of the shofar. Even Rabbi Yishmael who holds that the world was created in Nissan, agrees that Tishrei is Rosh Hashanah.

While the movements of the heavenly bodies are indeed continuous and have neither a beginning nor an end, there are differences in the physical nature of their relationships according to the months. For some months the earth is closest to the sun, while at others it most distant; the former being the hottest months of the year and its days are longest, while the latter are the coldest and the days are short. In both Nissan and Tishrei, the earth stands at an equilibrium point relative to the sun, the days and nights are of similar length and the temperature is most equally balanced, so that these 2 months seem appropriate to being the beginning of a new period. They both would seem to be, with regard to nature’s laws and the physical movements of the heavenly bodies, appropriate to being the beginning of a new year. However, Tishrei is the beginning of conception, the hibernation that marks the start of the birth, as it were, of the natural cycle. In the same way as we consider the night to be the commencement of all that is to come to fruition in the daytime, so too, this month is the commencement of all that is to happen in the physical world’s cycle; just as we mark the new day with the night before, so too, do we mark Tishrei as Rosh Hashanah. So Rabbi Yishmael can accept Tishrei as Rosh Hashanah, marking a new natural cycle, despite his ruling that the world was created in Nissan; created but as yet not to usher in a new physical and natural cycle. This cycle is not something given over to any decision or determining act of Mankind, it is purely a product of the forces of nature the movement of the heavenly bodies.

However, the months also differ according to another cycle, one determined by the associations and history that men ascribe to them, and thus determine their beginning and their end, even though there is no such thing in the movement of the heavenly bodies that mark time in the physical world. In this cycle, being independent of the natural order, men can see events, people or natural phenomena as being so significant as to constitute a beginning or an end to a particular segment of time; a new year. People calculated years from the Flood, the ancient Greeks counted their years from the siege of Troy, the Romans from Augustus Caesar, and the Ishmaelites from the days of their prophet. For us, the Exodus from Egypt, with its miracles that forced nature to behave contrary to its own laws, marks such a beginning, whereby Israel came to fruition as nature does in the spring of the natural cycle. So Nissan was to be Rosh Chodashim for the Jewish People, in their particular and specific national and spiritual cycle. So we number the months, with Nissan as the first month of the going out of Egypt, then the second month of our going out etc., even as we read in the Tanach. Since this was a cycle, independent of the Divinely created natural one with its laws and logic, human Man could determine its beginning and ending. So Moshe and Aharon could be commanded to mark this month as Rosh Chodashim and to make this incumbent on every generation.

“It is easier for human beings to relate to the Chagim than it is for them to relate to Shabbat and therefore their influence on us is by nature far stronger. Human courts determine when the Chagim occur and they all are reminders of events that are part of our history. Shabbat, however, is independently determined for us and it marks cosmic and universal events” (Shem Mi Shmuel of Sochochow).

“Hashem said to Moshe and Aharon saying, This month shall be to you….the first month of the year. Speak to the children of Israel saying,… it is Pesach to Hashem” (Shmot, 12:1-11). Why does the text distinguish between the mitzvah of Kiddush hachodesh in verse 2 and that of Pesach in the following verses, even though they were given to Moshe and Aharon at one time? Since the calculations and procedures to align correctly the solar and lunar years so that Nissan always is in the spring, are complicated and difficult, this commandment was given to Moshe and Aharon only [later to the Sages of each generation], in contrast to the laws of Pesach Mitzrayim, that are incumbent equally on all the people and so are taught to the whole House of Israel.

It is true that on the return from exile in Bavel, we brought with us the Babylonian names of the months that we still use, yet they were numbered only according to the Exodus and not according to some system reminiscent of their origins.

[It may be pertinent in this respect to note that even though we continue to use these Babylonian months, almost all halakhic authorities consider it forbidden to use the Christian years or any other that dose not bear witness to the Creation, as our years do. There are some, like the Chatam Sofer, who permitted the use of their date in conjunction with ours.]

Text Copyright &copy 2005 by Rabbi Meir Tamari and

D r. Tamari is a renowned economist, Jewish scholar, and founder of the Center For Business Ethics ( in Jerusalem.