Common Sense and the Dogma of a Single Egyptian Calendar System

[Modified 14 Oct 2024] (This post presumes the reader has a basic knowledge of the Egyptian calendar and the Sothic cycle. Please refer to the linked Wikipedia articles to clarify points.)

Two central premises in the conventional view of ancient Egyptian chronology are: 1) That the Egyptians employed only one calendar system throughout their history without any reforms or regional variants, and 2) With this fundamental principle, any anciently recorded Sothic date can yield a reasonable approximation of the year of that observation in the Julian calendar. However, does the evidence support these contentions? The following list of Sothic dates in probable chronological order raises an obvious question. Although many of the dates follow a sequence harmonious with the drift of Sothis through the Egyptian calendar, can we reasonably conclude that all of them do?

(Some of the festival calendars had the undated rising of Sirius immediately after another dated festival, implying Sothis was on the same or the following day. This table lists them with a “+” after the previous festival date.)

Through the combined statements of Censorinus and Theon, we learn that a “Great Year” (or Grand Sothic Cycle) had ended with the start of a new cycle on I 3ḫt 1 in 139 CE, that this cycle had lasted 1460 years [365 x 4], and that the Egyptians called this period the “Era of Menophres.” Are the Sothic dates in the table above harmonious with this idea? From the reign of Ramesses III, they are. However, several earlier dates contradict the hypothesis that the Egyptians used only one calendar system.

Furthermore, Merneptah and his son Seti II had birth names similar to “Menophres.” Since Merneptah had indeed ruled around 1460 years earlier (contrary to the conventional understanding), we see that the evidence supports the general accuracy of the concept of the Sothic Great Year.

Within a few years after the start of Ramesses III’s rule, the Sothic dates began in II 3ḫt. If the observer of the Medinet Habu Calendar (MHC) Sothic date were in the north, the Theban calendar used in the Eighteenth and early Nineteenth Dynasties would have already shifted to II 3ḫt. Yet, the MHC puts them in Ⅰ 3ḫt. The change back to Ⅰ 3ḫt implies a calendar reform between the Nineteenth and Twentieth dynasties.

Does common sense support the premise that no other calendar system existed in Egypt before the rule of Merneptah? The dates in the table above are inconsistent with this idea. Yet, many Egyptologists insist that we must accept this single calendar system dogma because, they say, there is no other way to date earlier dynasties. Is it reasonable to claim that a broken clock is better than none?

One scholar found robust evidence consistent with the idea that the Upper and Lower Egyptians had two separate calendar systems. In harmony with her idea, all the “II-šmw” and “III-šmw” dates in the middle of the table above are from an Upper Egyptian calendar (the Theban calendar). Nevertheless, many Sothic dates fit neither the Theban nor Menophres calendars. Yet that researcher insisted that all the historical dates had to fit one or the other. Although she displayed good lateral thinking, she lacked critical thinking and was prone to confirmation bias. We must avoid becoming so enamored with our own theories (or traditions) that we try to force the evidence to support the theory rather than following the evidence to better hypotheses, theories, and conclusions.

The Six Pillars of Second Millennium BCE Middle Eastern Chronology (to be published soon) anchors the Theban calendar system through international synchronisms and multiple astronomical records and allusions. It demonstrates a far more reliable way to date earlier dynasties than relying on dogmatic traditions.

An analysis of Sothic dates leads us to objective, common-sense conclusions that the Egyptians had multiple calendar systems, and some were predominant in some periods, whereas others were regional or local.