Egyptian Dates

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This page gives access to a set of conversion tables for determining the Julian equivalent of Egyptian civil and lunar dates in the Ptolemaic era. Two tables are provided: a table converting civil dates to Julian dates, and a table notionally converting lunar dates to civil dates according to the lunar cycle of pCarlsberg 9.

In this section, several topics are discussed:

The Regnal Eras

Ptolemaic dates according to the Egyptian calendar can only be converted into Julian dates once the relationships between the Egyptian regnal eras and the Julian year count are known. This section summarises the analysis on which these relationships are established. Note that it only covers the number of complete regnal years assigned to each king. For the evidence on precise dates within the first or final regnal year on which a change of ruler took place, to the extent that these can be determined, see the discussion under individual rulers.

The Canon of Kings of Claudius Ptolemy

The reign-lengths of Ptolemaic kings were accurately known, in the first instance, from the so-called Canon of Ptolemy, a kinglist contained in the Handy Tables of Claudius Ptolemy to allow easy conversions between regnal years and the years of the Era of Nabonassar. The canon was maintained and extended by Byzantine scholars throughout the Middle Ages. Its recovery and publication in the west was one of the major milestones in the development of scientific chronology in the 17th century.

The section of the list covering the Ptolemaic dynasty is as follows:


Reign length

Accession year
(Nabonassar Era)

Julian Date Range
(Accession Year, B.C.)

Ptolemy (I) son of Lagos



7 Nov. 305 / 6 Nov. 304

Ptolemy (II) Philadelphos



2 Nov. 285 / 1 Nov. 284

Ptolemy (III) Evergetes



24 Oct. 247 / 23 Oct. 246

Ptolemy (IV) Philopator



18 Oct. 222 / 16 Oct. 221

Ptolemy (V) Epiphanes



13 Oct. 205 / 12 Oct. 204

Ptolemy (VI) Philometor



7 Oct. 181 / 6 Oct. 180

Ptolemy (VIII) Evergetes II



29 Sep. 146 / 27 Sep. 145

Ptolemy (IX) Soter



21 Sep. 117 / 20 Sep. 116

Ptolemy (XII) Neos Dionysos



12 Sep. 81 / 11 Sep. 80

Cleopatra (VII)



5 Sep. 52 / 4 Sep. 51




31 Aug. 30 / 29 Aug. 29

Since Ptolemy used the Egyptian wandering year, it is straightforward to calculate the Julian accession year of each of these kings according to this table once one absolute date has been fixed. Several such dates can be determined from the astronomical data that Ptolemy provides in the Almagest. If the list can be shown to match contemporary data, it provides a basic Julian framework for Ptolemaic chronology.

It is clear from classical histories, notably Eusebius, Chronicorum I 161ff. (which uses the Olympic calendar, not the Egyptian one), and from the papyrological data, that the Canon is greatly simplified compared to the actual historical sequence of rulers. These sources show that the regnal eras of several Ptolemaic rulers are not mentioned in Ptolemy's list, and the papyrological sources further show that there also some Egyptian rebel kings who had regnal eras. However, the reason Ptolemy omitted these eras is clear: they did not contribute to his purpose in compiling the list. Some rulers (Berenice III, Ptolemy XI) are clearly omitted because they reigned for less than a year, while others (Cleopatra II, Cleopatra III, Ptolemy X, Cleopatra V, Berenice IV, Ptolemy XIII, Ptolemy XIV, Ptolemy XV, and the rebel kings Horwennefer/Ankhwennefer and Harsiesi) are omitted because their reigns were subsumed by the eras of rulers who were included in the list.

The second problem with the Canon is more complex: not all kings used a regnal era in which the epoch was 1 Thoth of their accession year. We are told by other sources that Ptolemy II and Ptolemy VIII both counted their regnal eras from the year they became coregent, rather than the year they became sole ruler, and that the regnal era of Augustus was initially based on the anniversary of the fall of Alexandria. Since Ptolemy's concern is with the length of reign, not with regnal year numbers as such, the eras for these kings in the list are clearly based on the epochs that made most sense to Ptolemy for dating astronomical events. However, it is not immediately clear how the astronomical year numbers of these kings in Ptolemy's list correspond to the regnal year numbers of the historical record.

Validating the Canon

Note: At the time I first wrote this section in 2005 I was not aware of any published validation of the Canon for the Ptolemaic period, its general correctness being just assumed. Louis Goguillon (whose website on calendars is available here) subsequently drew my attention to F. Robiou, Recherches sur le calendrier macédonien en Égypte et sur la chronologie des Lagides, which gives a very similar analysis, subject to the limits of the data available in 1877. Another similar analysis is given in M. L. Strack, Die Dynastie der Ptolemäer, 149ff., which includes discussion of a couple of additional documents not considered in my original discussion; I have added these.

There are several types of contemporary data that we can use to test the reign lengths in Ptolemy's list, to determine the dates of rulers not mentioned in the list, and (where necessary) to determine the relationships between the eras of the list and the regnal eras of the historical record. The contemporary coverage is sufficiently complete that the Canon is not only fully vindicated but may be considered replaced by this data as the foundation of Ptolemaic chronology.

The most important confirmations are:

Highest Regnal Years

The highest attested regnal years for the kings in the Ptolemaic Canon are as follows:


Reign length

Highest attested year


Ptolemy (I) son of Lagos



pdem BM 10.537

Ptolemy (II) Philadelphos



BGU 6.1463

Ptolemy (III) Evergetes



pEnt 97

Ptolemy (IV) Philopator



pMed. Inv 83.03

Ptolemy (V) Epiphanes



pColl Youtie 1.12

Ptolemy (VI) Philometor



pdem Fuad I

Ptolemy (VIII) Evergetes II



Edfu VII 9.3

Ptolemy (IX) Soter



Brugsch ZÄS 24#51

Ptolemy (XII) Neos Dionysos



OGIS 190

Cleopatra (VII)



pOxy 12.1453

This table glosses over issues of identifying the kings in the source data, e.g. Ptolemy XII changed his epiklesis from "Philopator Philadelphos" to "Neos Dionysos" part-way through his reign. The assignment of some of the sources, e.g. those for Ptolemy III and IV, are determined indirectly, usually on prosopographical grounds, which may risk inducing circular reasoning, although I do not think there is any. The resolution of such issues is discussed under individual rulers.

The case of Ptolemy I, marked in blue, requires separate discussion. The literary sources explain that Ptolemy II accounted his years from the date of his coregency with Ptolemy I, which was two years before his actual accession. For this reason, the generally accepted reconstruction of Ptolemy I's chronology predicts a highest Egyptian regnal year number of 23, not 21, since his last two years were in coregency with Ptolemy II. While the highest attested year number of 21 accords with the Canon, this means that it is not sufficient proof that his Egyptian regnal years only covered the 20 years of the Canon, although that position has been argued recently by B. Muhs, Fs. Pestman 71. However, this analysis is based on tax receipts, which used a financial year, at this time equivalent to the Macedonian regnal year. Moreover, if correct Muhs' solution implies discrepancies with the dates recorded according to his Macedonian regnal years, which certainly carried on to his death. Muhs' solution implies that some Greeks dated according to Ptolemy I while other Greeks in the same place, and Egyptians, dated according to Ptolemy II. Further, iBucheum 3 (discussed below) is clear if indirect evidence of 22 completed Egyptian years, notwithstanding Muhs' attempt to argue this datum away through the form of the numeral. On these grounds, this particular "highest year" is unlikely to be accurate.

The probable explanation of the absence of higher dates is simple lack of evidence. Our attestations for regnal years of Ptolemy I are very sparse compared to those of later kings. At least as of 1967, we had no attestations for Egyptian years 1, 3, 7, 9-10, 15 and 19 -- a third of his reign (P. W. Pestman, Chronologie égyptienne d'après les textes démotiques, 13-15). For the rest of the Ptolemaic era, there are dated records from almost every year. For this reason, the attestations can reasonably be taken as reliable indicators of the highest actual regnal years from Ptolemy II onwards.

It is clear that in general the highest attested year is one greater than the reign length assigned by Ptolemy. This shows that the first regnal year of an incoming king usually annexed the last year of his predecessor. The two clear exceptions, marked in blue, are explicable by departures from that custom, for reasons explicitly discussed or clearly traceable in the sources:

Direct Statements of Reign Length and Distanzangaben

These two classes of evidence are treated together.

There are two documents giving explicit statements of reign length:

Additionally there are at least two documents showing an implicit regnal transition:

Distanzangaben are provided by funerary stelae of priests and sacred animals, most importantly the Buchis bulls, which give an explicit birth date, death date, and distance between the two. When the birth and death dates are in the reigns of different kings, it is easy to determine the total number of years for the reigning king's predecessors, back to the king reigning at the time of birth. For the sacred bulls in particular, the two kings usually reigned consecutively. However, the calculations on the stelae are not always accurate. This is usually not a problem if the error is in months or days, but in some cases the error apparently is in the calculation of years.

The useful Distanzangaben I have located of this type are as follows (if you know of others, please email me). Dates are given in the format dd/MM/<regnal year>, where the Roman numerals give the position of the Egyptian month. Corrections and completions are shown in [green]; note that Egyptians often omit the 5 epagomenal days in calculating lifespans:






iBucheum 3

Buchis of Thenuhab

19/X/14 Pt. I

25/VI/13 Pt. II

20y 8m 13d

Vienna 153

Anemhor II HPM

3/VII/16 Pt. I

26/VIII/5 Pt. IV

72y 1m 23d

Berlin 2118

Kha'hapi, priest

14/VII/11 [Pt. II]

4/V/2 [Pt. V]

69[68]y 9m 20d

Vienna 154

Djedhor HPM

29/XI/18 [Pt. II]

23/VI/24 [Pt. III]

43y 6m 29d

iBucheum 6

Buchis of TaAmen

20/XI/13 [Pt. III]

12/X/8 Pt. IV

18y 5[10]m 23d

BM 378

Heriu II HPL

24/X/8 Pt. IV

26/III/7 Pt. VIII

50y 6[5]m 5[7]d

Brugsch ZAS 22#6

Apis of Ta-Renenut II

13/IV/19 Pt. V

6/VII/6 Pt. VIII

22y 2m 23d

iBucheum 8

Buchis of Ti-Khnumt

2?/VII/25 Pt. V

7/V/19 Pt. VI

17y 9m 6d 11hr

iBucheum 9

Buchis of Ti-Khnumt

3/VII/19 [Pt. VI]

27/XII/36=25 Pt. VIII

17y 5m 20d

Vienna 82

Pedubast III HPM

1/III/50 Pt. VIII

7[?2]/VI/5 Pt. XII

43[44]y 2[3]m 2[?6]d

Ashm 1971/18

Psherenptah III HPM

21/II/25 Pt. X

16/XI/11 Cl. VII

48y 7[9]m

BM 377

Taimhotep his wife

9/IV/9 Pt. XII

16/VI/10 Cl. VII

30y 2m 6d

iBucheum 13

Buchis of Tenen

12/VII/28 [Pt. XII]

21/VIII/1 Caesar

24y 1m 8d

Brugsch Thes. V 934

Woman Nefer-Ho

13/V/19 Pt XII

18/II/7 Caesar

38y 9m 10d

pdem Rhind 1

"Archon Sauf" (Strack)

27/III/13 Pt. XII

10/XI/21 Caesar

59y 7m 14d

I have found two other documents that give similar Distanzangaben data:

Working backwards through the monarchs of the Canon:

Hence the contemporary data generally supports the Ptolemaic Canon, and explains some of the simplifications in it, although it is also clear that if we had to reconstruct Ptolemaic chronology solely on the basis of the contemporary data there would be some discrepancies that would be quite controversial.

The Non-canonical Regnal Eras

Having established the validity of the Canon, the next step is to establish the non-canonical regnal eras. The accession-based count of Ptolemy II and the coregency-based count of Ptolemy VIII have already been discussed in connection with the Distanzangaben. There is one remaining Distanzangabe, which gives the most important of these eras:

The synchronisation between the canonical regnal eras and the remaining non-canonical regnal eras can be derived from the double dates. These occur for a number of reasons, and not all of them are useful in establishing the position of one reign relative to another. Details are discussed under individual rulers. The following double dates indicate the start of non-canonical eras:

The Regnal Eras of the Rebel Kings

Finally, there are the regnal eras of the rebel Egyptian kings Horwennefer/Ankhwennefer and Harsiesi. There is no direct synchronistic data which tells us how the era of Horwennefer/Ankhwennefer is related to those of the Ptolemaic rulers. Rather, the dates are bounded by the internal evidence of the papyri and inscriptions. The era has recently been established by a subtle and complex analysis which I have tried to summarise on the page for that king. For Harsiesi, the synchronisation is a little more direct, since his rule in Thebes is inferred from a papyrus of year 40 of Ptolemy VIII; however there is some doubt whether the "enemy of the gods" referred to there is the same as the late period pharaoh Harsiesi.

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