Counting the Jewish Years

How the Jewish year is numbered.

The Jewish calendar not only has its own unique months, but it also numbers years differently from the secular calendar.


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The counting of Jewish years, as we know it today, dates from the Middle Ages. In secular texts, Jewish time is often noted as “A.M.” — anno mundo — literally, “years of the world.” (Occasionally, “A.M.” is explained as standing for aera mundi, “era of the world.”) This system of Jewish time is called the “Mundane Era” (English for aera mundi) because those who invented it believed they were calculating dates from the birth of the world.

Chronologies of the Bible and Temple

The basis of the Jewish annual calendar is ancient. The Torah speaks of the annual cycle of holy days and festivals, and it was systematized by the sages well before the fall of the Second Temple in 70 C.E.

If one tries to ascertain the origin of our counting of years, however, the Bible does not seem particularly helpful. When providing a history, the Bible refers to lifetimes. For example, the Torah tells us that Abraham was 75 years old when he and his household were sent from Haran to Canaan (Genesis 12:4). In the books of Samuel, Kings, and Chronicles, dates are generally given according to the years of a sovereign’s rule.

Most often, the dates are consistent among these five books. During the time when two kings ruled the divided kingdoms of Judah and Israel, the ascendance of one state’s king might be given relative to the years of the other king’s reign. For example, II Kings 14:1 reads: “In the second year of [the reign of] Yoash ben Yoahaz, King of Israel, Amatzyahu ruled [i.e. came to the throne] as King of Judah.”

During the fourth century B.C.E., a dating system was sought out for secular use on business and legal documents. At this time, the Jews borrowed the practice of the Greeks, who had introduced the practice of numbering time in “eras”–periods of time relative to a historical event, rather than the lifetime or rule of any one person. This new system is called the “Seleucid Era” by secular scholars and, in Jewish circles, it is known as “minyan shtarot”–“accounting of contracts.” It counts time from the year 312-311 B.C.E., supposedly six years following the arrival of Alexander in the Land of Israel.

For private records and Temple histories, a different era was established, one measured from the Exodus from Egypt. An example of this can be seen in I Kings 6:1, where the date for the construction of the First Temple is given as 480 of the Exodus era.

Calculating the Birth of the World

The Tannaim (sages of the late Second Temple Period and the century after the destruction) calculated the date of Creation. They did so by basing their work upon the Bible’s account of lifetimes and kingdoms, thereby determining the period of time from Creation to a known date, in this case, the destruction of the Second Temple in 70 C.E.

Many rabbis attempted this task, but the method attributed to Rabbi Yossi ben Halafta, a second century C.E. sage, is the one which gained popularity. He calculated “molad tohu”–“birth from nothing”–to be in the fourth hour of Monday, October 7, 3761 B.C.E. (according to the Gregorian calendar used in the secular world today). In Hebrew, this moment has the mnemonic acronym “BeHaRD”, which stands for:

Bet: the second day of the week, Monday (since the letter bet often represents the number two);

Hei: the fifth hour (since hei represents five);

Reish-Daled: 204 halakim (“parts,” a smaller measure of time, based on the idea that reish=200, daled=4).

The calculation of BeHaRD is discussed in a work attributed to Rabbi Yossi, Seder Olam (“Order of the World”), which is also sometimes called Seder Olam Rabbah in order to distinguish it from a work of similar name (the later Gaonic work, Seder Olam Zuta).

Innumerable scholars, both Jewish and Christian, have attempted to calculate the date of Creation. Even if they used the same basis (Tanakh, the Hebrew Bible) for their systems of accounting, there is a broad range among their estimates. The historian des Vignoles stated in the introduction to his treatise on chronology that he had found well over 200 different calculations of the time from the birth of the world to the fall of the Second Temple, and that they varied by as much as 3,500 years. Well into the rule of Queen Victoria of England the most commonly given date for Creation was the year 4004 B.C.E., calculated by Bishop Usher, who published this date in 1654.

To this day, those Jews who believe the biblical accounting of time to be literal still accept Rabbi Yossi’s calculation, dating Creation to the year 3761 B.C.E. Others claim that the date is figurative, symbolic, or holds esoteric meaning. In calculating BeHaRD, Rabbi Yossi tried to justify disparate accountings from the following sources: the chronologies of Samuel, Kings, and Chronicles; those of the Second Temple kingdoms, in rabbinic histories passed down to the Talmud and found in the Babylonian Talmud, Avodah Zarah 9a and 10a; and the prophecies of Jeremiah and Daniel.

Some academics compare the Genesis accounting of dates with those of the Greeks, Chaldeans (including the Babylonians), Egyptians, and Hindus. The Chaldeans, Egyptians, and Hindus used enormous figures, into the millions of years, to explain the timeframe of Creation. The ancient Hebrews and Greeks seemed unwilling to deal in such large numbers. Both peoples ascribed Creation to a date closer to their own times. This may indicate either a political agenda (consciously or subconsciously communicating a cultural chauvinism) or may simply be a simplification for the purpose of clarity.

It is possible that there is a direct correlation between the seven days of Creation mentioned in Genesis and a specific Babylonian system, which would suggest that each Genesis “day” represents a specific number of solar years.

Establishment of the Mundane Era

The Seleucid and Mundane Eras coexisted for numerous centuries. Most often, Rav Sherira Gaon — the last Gaon, the head of the academies in Babylonia in the centuries following the editing of the Talmud — is given the credit for suggesting the use of BeHaRD as the basis for a chronological system, in the 10th century C.E.

Maimonides (1135-1204 C.E.) at times used multiple eras, giving a date first according to the years following the destruction of the Second Temple, then according to the Seleucid Era, and finally according to the Mundane Era. This suggests that no single system had achieved universal acceptance by the 13th century.

The Seleucid Era continued to be used in parts of the Arab world until quite late. Among Egyptian Jewry, it was the dominant system used until Rabbi David ibn Abi Zimra discontinued its use in the 16th century C.E.; in parts of the Arabian Peninsula, it was used alongside the Mundane Era as late as the 19th century.

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