Gezer Calendar and Lunar calendar

Question

Do the paleo-Hebrew inscriptions of the Gezer calendar, dated around the 10th century BCE, suggest that at one time the ancient Israelites used a strictly lunar calendar?

The calendar is written crudely in paleo Hebrew on stone. The inscription goes something like:

"Two months of harvest Two months of planting Two months are late planting One month of hoeing One month of barley-harvest One month of harvest and festival Two months of grape harvesting One month of summer fruit"

The word "month" is translated to mean "moon", according to online sources. There's no indication of a possible 13th month; neither are any of the months named to give an indication as to when in calendar year did the harvest begin etc. This possibly suggests that the years were strictly lunar, with harvest time etc occurring in various months throughout a typical decade.

If it doesn't indicate a strictly lunar calendar, would it point to the notion that a typical year would've been pictured as 12 lunar months?

Answer 1

I do not think it suggests that the ancient Israelites used a strictly lunar calendar for a number of reasons:

1. There is no evidence that the Gezer calendar is meant to be a calendar in the sense of setting forth a normative year. It is a description or proscription of the farming that would take place over a year, broken down by months. It might very well be a farming plan for a specific farm for a specific year.

2. A typical year in the Jewish calendar is 12 lunar months. And leap months in biblical and second temple times were added every few years but were not added until the end of the year, so any prospective statement would presume 12 months.

3. The word for month ירח comes from the hebrew word for "moon" (just like the english word "month") but came to mean month in general, not just a lunar month. Therefore, the mere fact that the term used is ירח does not mean that it was strictly lunar at that time.

I am editing this answer because I have come across a Baraisa quoted in Baba Metzia 106b that is astonishingly similar to Gezer calendar. The Baraisa quotes a three-way dispute about the agricultural seasons:

רשב"ג משום ר"מ אומר וכן היה רבי שמעון בן מנסיא אומר כדבריו חצי תשרי מרחשון וחצי כסליו זרע חצי כסליו טבת וחצי שבט חורף חצי שבט אדר וחצי ניסן קור חצי ניסן אייר וחצי סיון קציר חצי סיון תמוז וחצי אב קיץ חצי אב אלול וחצי תשרי חום רבי יהודה מונה מתשרי ר"ש מונה ממרחשון

Rabbi Shimon ben Gamliel from Rabbi Meir said, and so to did Rabbi Shimon ben Menasia say like his words: Half of Tishrei, Marchesvan, and half of Kislev is the planting season; half of Kislev, Teves, and half of Shevat is the winter season (but the Gemara explains that this is the late planting season for barley and legumes); half of Shevat, Adar, and half of Nissan is the cold season; half of Nissan, Iyar, and half of Sivan is the harvesting season; half of Sivan, Tammuz, and half of Av is the summer season, and half of Av, Elul, and half of Tishre is the hot season. Rabbi Yehuda counts (the agricultural cycle) starting in Tishrei. Rabbi Shimon counts (the agricultrual cycle) staring in Marcheshvan.

To me this makes clear that the Gezer calendar--just like the Baraisa--is an agricultural calendar setting forth the ideal times for planting, harvesting, etc. in Eretz Yisrael.

Answer 2

It is disputed by scholars as to whether the Gezer Calendar is of Israelite origin in the first place.

The calendar could very well be written in the Phoenician language, Proto-Canaanite, or Paleo-Hebrew, as all three languages share the same alphabet and root vocabulary.

Since there is no definite proof that the calendar was written by the Israelites, we cannot determine for sure whether or not the Israelites once used a strictly lunar calendar. However, I would always trust thousands of years of tradition over an archeological discovery.

Answer 3

If "yrh" in the Gezer calendar means a lunar month, then the calendar must have been intercalated periodically or the agricultural activities would have fallen out of synchronization with the months.

There is always the possibility that it describes a solar calendar like the Egyptian calendar. This calendar did not have a fixed relationship to the seasons, but over a single human lifetime the relationship would have been stable.

Answer 4

The Jewish people (Israelites) are bound by the Biblical command to have Passover in the spring as it says in Devorim 15 (1):

Keep the month of spring, and make the Passover offering to the Lord, your God, for in the month of spring, the Lord, your God, brought you out of Egypt at night.

On which Rashi says from the Gemoro:

Keep the month of spring: Heb. אָבִיב. Before it [Nissan] arrives, watch that it should be fit for the אָבִיב, ripening [capable of producing ripe ears of barley by the sixteenth of the month], to offer up in it the omer meal offering. And if not, proclaim it a leap year [thereby enabling you to wait another month, until the barley ripens]. — [San. 11b]

A purely lunar calendar is 354 days. The solar year is approximately 365 days. Without the use of a leap year, Passover could not always be in the spring. The intercalation of a leap month keeps the lunar calendar in line with the seasons. So it is not possible that the Jewish people could have used a purely lunar calendar.