Shabbat Ha-Chodesh: Introducing the Jewish calendar

• Published date: 11 March 2021
• Author: Daniel Pinner
• Date: 11 March 2021
• Publication title: Israel National News (Israel)

The name is derived from the Maftir, the reading which concludes the Torah-reading. Instead of being a repetition of the final several verses of the Torah-reading (as it usually is), the Maftir for this Shabbat is instead Exodus 12:1-20:

"Hashem spoke to Moshe and Aaron in the land of Egypt, saying: הַחֹדֶשׁ, this month will be the first of your months…"

This is the basis of the Jewish calendar: it is the commandment that we calibrate our own calendar, with the month of Aviv (Nissan) as the first month. It also implies obliquely our entire calendar-system: the months are calibrated from new moon to new moon, and the year has to be calibrated such that Nissan invariably falls in the spring-time, hence the system of leap-years in which we have an extra month.

In order to understand the significance of having our own calendar, let us go back to the day that G-d gave this mitzvah:

It is the first of Nissan in the year 2448 (1312 B.C.E.). Nine of the Ten Plagues have struck Egypt, and only the tenth, the Slaying of the Firstborn, the most devastating Plague of them all, is yet to come. But that is still two weeks in the future.

The Jewish nation is poised on the very threshold of freedom. After 210 years of exile in Egypt, we are just two weeks away from the Exodus. The slavery is already a thing of the past, a recent and bitter memory, but we are still imprisoned in Egypt, as yet unable to leave.

And it is now that G-d gives us our first-ever national Commandment: "Hashem spoke to Moshe and Aaron in the land of Egypt, saying: This month shall be the head of your months – it will be the first of the months of your year".

It is of course deeply significant that establishing our own calendar marks the end of slavery: a slave needs no calendar, no clock. A slave has no need to calibrate or to measure time. He eats, sleeps, works, lives his entire life according to his master's schedule and commands.

And the corollary is that a free nation needs its own calendar to govern its own life.

And so it is no coincidence that it is specifically Pesach, the Festival which celebrates our freedom from Egyptian slavery, which calibrates all of our Holidays.

Almost three-quarters of a millennium ago, the Ba'al ha-Turim (Rabbi Ya'akov ben Asher, Germany and Spain, c.1275-1343) designed a simple method of calculating which day of the week any given Festival will fall on by its relation to Pesach (Arba'ah Turim, Orach Chaim 428:5).

He used the א"ת ב"ש (pronounced "atbash") system...