JUDAISM | Understanding the Jewish calendar

According to tradition, the calendar used by Judaism originated with the creation of the world, exactly 3,760 years before Christ. This calculation is made using the age of the people and events mentioned in the Torah. This calendar now has a number of variants, with the most widespread being what is known as the Rabbinic Torah.

Although the Jewish calendar was originally based on the criteria of observation, starting in the 4th century AD mathematical calculation has been used to establish the twelve months of the year and the corresponding religious festivals. As this is a lunar-solar calendar, it is necessary to correct for the lag between the solar cycle and the shorter lunar cycle. This is done using a methodical combination of years with twelve and thirteen months, in a cycle of nineteen years (the Babylonian saros cycle or the Greek Metonic cycle). When the year has thirteen months, it is called a embolismic or intercalated year (shana meuberet), i.e., a leap year or bissextile year. The extra month is called adar alef or adar rishon, as it “duplicates” the month of adar. The Jewish bissextile year should not be confused with the leap years of solar calendars, where what is added is not a month but days, in order to round up the solar cycle. It is also important to remember that the embolismic year of thirteen months is not mentioned in the Tanakh at all.

In this lunar-solar calendar, the solar cycle is important for determining festivals of an agricultural nature, while the lunar cycle is important for determining the start of the months, which always begin with the new moon. It should be remembered that in Judaism, it is customary to celebrate the beginning of each month (rosh hodesh). The oldest names of months in the Jewish calendar are of Phoenician origin, but the ones currently in use come from the period of exile in Babylon ( 6th century AD).

The Book of Exodus (Shemot) establishes the start of the year in the month of Nissan, which commemorates the departure from Egypt; while Leviticus (Vayikra) states that New Year‘s Eve (rosh hashanah or yom teruah) should be celebrated in the month of Tishri, which commemorates the creation of the world. It may seem like a contradiction, but as with most festivals, much of the confusion can be cleared up if it is related to astronomical and, in turn, agricultural phenomena. Traditionally, the solar cycle is divided into four  seasons that are marked by two solstices and two equinoxes: Nissan includes the spring equinox and the harvest period; Tishri includes the autumn equinox, the harvest period.

The Jewish calendar places a great deal of importance on the week (shavua), as this reproduces the six days of creation and the day that God took off to rest. The days  (yom) begin and end at sunset (ereb), which has its equivalent in the solar cycle with the autumn equinox. The seventh day of the week is called Shabbat because it is the day of rest and the day when all Jewish people must stop working and dedicate themselves to prayer, visiting the synagogue and staying at home with their families.

Judaism also prescribes rest every seven years, with what is known as the sabbatical year (shmita). Its most visible consequence is the fact that fields are left fallow: agriculture has proved the benefits of the practice known as setting aside. After multiplying “seven times seven”, the fiftieth year marks a celebration known as the Jubilee Year (Yobel), characterised by reconciliation and forgiving debts.

Some symbolic examples from the calendar

Symbolic interpretation does not question or deny its historical or religious nature. In regard to temporal expression, calendars have an eminently cyclical nature, which mainly links them with numerical, geometrical and astronomical symbolism.

The twelve months of the year are directly related to the solar symbolism of the twelve signs of the zodiac. For example, sacrificing the Easter lamb in the month of Nissan, is related to the ram in the Aries constellation. It is very difficult not to see allusions to solar symbolism in Enoch‘s lifespan of 365 years, or the time Noah spent in the Ark during the flood.

The four lunar phases determine the month and the menstrual cycle. For example, the relationship between women and the moon is clearly referred to in the Talmud, when speaking about rosh hodesh and its particular prayers (kidush halevana).

The weekly cycle clearly expresses a lunar phase and also reflects the symbolism of the septenary planet system, something that also occurs in many European languages. In regard to sabbatical and jubilee cycles, they express, in a temporal language, the same meaning as the “fixed centre” in the middle of the six spatial directions. For example, the Zohar recalls how Jeremiah related the Jubilee Year to a river in Paradise.

The alphanumerical value of the Hebrew language, widely developed by the Kabbalistic method of gematria, is often used to understand the hidden aspects of words. For example, it is said that the numerical value of the Hebrew word for year (shanah) is 355 (Shin 300 + Nun 50 + He 5), which is equivalent to the number of days in the prototype Jewish calendar. According to temurah, a science that studies the permutation of letters, the same word, shanah, would express a hidden meaning in the word nahash. In reality, the annual cycle cannot be considered a closed or circular cycle, but rather as an open or spiral cycle, similar to the movement of a snake (nahash), like the one responsible for Adam and Eve‘s fall from grace. If time is considered a purely quantitative succession, in the Aristotelian fashion, it is represented as an unfolding; but if it is considered qualitatively, as in religious calendars —establishing their festivities— then it is represented as folding.