Calendar Controversies, Lawrence H. Schiffman, Reclaiming the Dead Sea Scrolls, Jewish Publication Society, Philadelphia 1994.

The Dead Sea Scrolls
Because the calendar used by Jews in this period and the controversies surrounding it run as a leitmotif throughout our discussion of prayer, sacrifice, and the Temple in Qumran texts, it is appropriate here to outline this controversy and its ramifications.

Numerous texts in the Qumran sectarian corpus castigate the sect’s opponents for observing the holidays on the wrong dates. Among the instructions to the sectarians is the following-

And to observe the Sabbath day according to its specification and the Festivals and the day of the fast according to that derived by the members of the new covenant in the land of Damascus … (ZADOKITE FRAGMENTS 6-18–19)

Clearly, this text alludes to observance of the Festivals and the Day of Atonement (Yom Kippur) according to the calendar of the Dead Sea sect.

We learn more about the calendar dispute from the description of the confrontation between the Teacher of Righteousness and the Wicked Priest (Pesher Habakkuk 11-4–8), discussed earlier. This text describes the Wicked Priest’s appearance at the sectarian center, presumably Qumran, and the ensuing confrontation. Significantly, the text records that this confrontation occurred on the Day of Atonement, when all Jews would have shunned travel, clearly forbidden on a day of rest. However, we are told that the Wicked Priest traveled to the teacher’s place of exile on Yom Kippur. We can make sense of this text only if we assume that these two groups were using different calendars so that the sacred Festivals fell on different days.

We have considerable evidence about the peculiar sectarian calendar, and we also know that it was used by other groups of Second Temple Jews as well. Drawing upon a variety of Qumran texts, most only recently released, we can reconstruct the sect’s calendar in its entirety. We know from talmudic sources that the Boethusians, a group of Second Temple Jews closely linked to the Sadducees, as well as the authors of the apocryphal books of Jubilees and Enoch, advocated this same calendar.

The calendar consisted of three hundred sixty-four days, divided into twelve months of thirty days each. The months were calibrated according to the cycle of the sun. At the equinoxes and solstices at the end of each three-month cycle, a thirty-first day was added to that month.

This calendar helped the sectarians solve a thorny problem- establishing the date for the holiday of Shavuot. According to the Bible, the Israelites were to bring the Omer sacrifice, the sheaf of barley, beginning on the morrow following the “Sabbath” after Passover (Leviticus 23-15). From that day, they were to count forty-nine days, and on the fiftieth day they were to celebrate the holiday of Shavuot, the Festival of first fruits of wheat.

Followers of the Pharisaic-rabbinic tradition began their counting on the day after the first day of the Festival, because they understood “Sabbath” to mean “Festival,” referring in this case to the first day of Passover. In contrast, the Dead Sea sect and the Boethusians interpreted “Sabbath” literally, so that they began their count on a Sunday. We now know from the Qumran evidence that this was the Sunday after the last day of the Festival. Under this system, the first day of the counting as well as the holiday of Shavuot always fell on a Sunday. The sectarian solar calendar guaranteed the sectarians’ legal interpretation of the Torah.

But this calendar had one major disadvantage- it was short by a day and a quarter each year. We have no idea how the sect dealt with this problem. Scholars are divided over the question, some theorizing a system of intercalation—that is, adding extra days—that would equalize this otherwise imprecise calendar. It is more likely, however, that this calendar was never really put to the test except perhaps for a short period on the part of some of the sectarian groups.

In contrast, the calendar of the Pharisaic-rabbinic tradition, still in use today, used such a system of intercalation. That calendar consisted of twelve lunar months, totaling three hundred fifty-four days, to which every three years or so a month was added, thus bringing the calendar into harmony with the solar year and aligning the Festivals with their proper seasons.

Which calendar—solar or lunar—represents the original calendar of biblical Israel? Various evidence points to the lunar (Pharisaic-rabbinic) calendar, although we have no direct information about the process of intercalation in biblical times. The Hebrew language itself provides a clue. The Hebrew term for month, hodesh, refers to the new moon; another word for month, yerah, is derived from yareah, which denotes the moon itself. How else can we understand these terms except in the context of a lunar calendar system? Furthermore, it is unlikely—over the long biblical period—that a solar calendar for which no intercalation system is known would have functioned successfully.
But despite these arguments, some scholars claim that the biblical calendar was a solar one, and that the lunar (Pharisaic-rabbinic) calendar was an innovation. This theory implies that the sectarian groups continued to use the ancient calendar even after the Pharisees had changed it. In my view, evidence from the Halakhic Letter has decisively challenged the plausibility of this theory. For if such were the case, why did the sectarians in all their various polemics against their Pharisaic opponents not accuse the Pharisees of changing the calendar?

At the beginning of one manuscript of the Halakhic Letter, we find a three-hundred-sixty-four-day calendar. At the end of the calendar, just before moving on to the Halakhic Letter, the text says-

And (thus) is the year completed, three hundred and six[ty four] days. (HALAKHIC LETTER A20–21)

Apparently, the scribe regarded this issue as so central to the founding of the sect that he appended a calendar text to the Halakhic Letter to fill in what he felt was missing. But why is this calendar missing in the text of the letter itself? We must conclude that the sect’s founders did not accuse the Pharisees of changing the calendar because the Pharisees were in fact following the ancient calendar inherited from biblical times.

For reasons we cannot know, various groups of priests and others in this period apparently wanted calendar reform, replacement of the lunar calendar with a solar one. This demand was shared by a number of groups represented in the Qumran caves. However, the solar calendar is not the only one represented at Qumran. The Daily Prayers apportioned for the days of the month are in fact keyed to a lunar month. Did the Qumran sect use both calendars? Or do the materials based on the lunar calendar reflect the views of others outside the sect? Some scholars have suggested that the sect did indeed use both calendars and had developed a system for synchronizing them.

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