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Cited by 1Ancient Egypt and ArchaeologyHistorical Astronomy and Related StudiesClassical Antiquity Studies

Movable wAgj and Numeration of Lunar days in Ancient Egypt

Open access
Puchkov, A.·2023·The Oriental Studies
DOI 10.15407/skhodoznavstvo2023.92.093
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Abstract

The ancient Egyptians celebrated the wAgj feast, an integral part of the Osirian cult. Data from the Illahun archive evidence that there were two instances of it: a fixed one, which fell on a specific civil date, and a movable one associated with a specific phase of the moon. There is disagreement about the lunar day and month on which the movable feast took place. The aggregation of the Illahun lunar dates into a ‘date net’ indicates that the disagreement is due both to peculiarities of the datasets of previous studies and to the incorrect numeration of lunar days in Parker’s list, which has been the standard for more than 70 years. Analysis of the lists of lunar days from the Ptolemaic Period also reveals the erroneous position of one of the days; when it is set to the proper position, the symmetry of the phases relative to the day of full moon improves. Based on the corrected numeration of lunar days, it is concluded that the movable wAgj in the original list fell on the 17th day of the second month after the emergence of Sopdet (the heliacal rising of Sirius in modern terms). Further research is needed to examine the effect of the proposed correction on the chronology of the Middle Kingdom.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper argues that Parker’s standard numeration of ancient Egyptian lunar days is off by one because psD(n)tjw was an unnumbered intercalary day and Abd began the lunar month; correcting this places the movable wAgj on LD 17 in the second lunar month after the heliacal rising of Sirius. It also identifies a corruption in the lunar-day list and calls for further research on the correction’s effect on Middle Kingdom chronology.

Key findings

  • With the corrected numeration assuming Abd = LD 1, the movable wAgj falls on LD 17 (16.85), psD(n)tjw on LD 30 (29.91), and smdt/mDdj-nt on LD 15 (14.96). Illahun movable wAgj dates average 60 days after prt Spdt, i.e. in the second lunar month after the heliacal rising.
  • Parker’s list should not begin with psD(n)tjw as LD 1; psD(n)tjw was an unnumbered intercalary day heading the lunar month, while Abd was LD 1. The list was corrupted sometime after the Middle Kingdom: mspr 2-nw was moved down, and restoring it improves phase symmetry (smdt surrounded by two sjAw; quarter intervals normalized).
  • The three-day interval between smdt and wAgj in pBerlin 10165 is inconsistent with the rest of the data; the smdt date from pBerlin 10165 needs correction from II Smw 19 to II Smw 20. The pBerlin 10282b Abd–smdt pair is excluded because III Axt 13 and III Axt 29 are separated by 16 days, whereas the interval between LD 2 and LD 15 should be less than 14 days.
  • Earlier disagreement is summarized as Krauss holding LD 17; Luft’s date net indicating LD 18 with full moon on LD 16; and Depuydt and Spalinger accepting LD 18 following Luft. The paper concludes the movable wAgj fell on LD 17.

Methods

  • The study aggregates Illahun lunar dates into a “date net” and checks four datasets: psD(n)tjw, Abd, smdt, and wAgj. It applies three date-selection rules: use original phase dates rather than calculated ones; exclude documents with conflicting dates (discrepancy of two or more days); and require dates of the same phase to be consistent within less than one day.
  • It uses the distance method from psD(n)tjw as LD 1, computing ΔLM = ΔD / 29.53059 and deviations, then excludes short intervals from pBerlin 10056 and pBerlin 10006. It recalculates the average lunar days assuming Abd = LD 1.
  • It also analyzes Parker’s 30-name lunar-day list and lists of lunar days from the Ptolemaic Period to identify the misplaced day.

Limitations

  • The paper states that further research is needed to examine the effect of the proposed correction on the chronology of the Middle Kingdom. It also notes scarcity of documentary evidence and no consensus on the day of the movable wAgj.
  • Evident from the text: conclusions depend on a limited Illahun archive and Ptolemaic lists; some dates are excluded or corrected; and prt Spdt dates are given as ranges due to different reign-date estimates, producing intervals such as 49–58, 56–64, and 59–67 days. The proposed correction’s chronological impact is not tested here.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.15407/skhodoznavstvo2023.92.093

Cites

22 of 22 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 24 cited sources checked · 0 supported · 0 flagged

  • Findingcitation

    pBerlin 10016 indicates that the movable wAgj took place two days after the full moon (2-nw n mDdj-nt).

    “pBerlin 10016 indicates that the feast took place two days after the full moon (2-nw n mDdj-nt) [Krauss 2006b, 425]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Krauss 2006b, 425

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Findingnone given

    The lunar wAgj follows prt Spdt in the Middle Kingdom lists.

    “The lunar wAgj follows prt Spdt in the Middle Kingdom lists, and its dates were calculated by the Egyptians according to certain rules that need to be clarified.”
    Quote in the paperSubstantial claim
  • Findingown data

    The consistency check indicates that the date from pBerlin 10165 needs to be corrected (II Smw 19 -> II Smw 20).

    “The consistency check (indicates that the date from pBerlin 10165 needs to be corrected (II Smw 19 -> II Smw 20).”
    Quote in the paperSubstantial claim
  • Findingown data

    For all four psD(n)tjw dates, taken as LD 1, the same pattern of relative positions of Abd / smdt / wAgj is observed: Abd / Abd + 14 / Abd + 16, where Abd varies from 1.36 to 1.96.

    “for all four psD(n)tjw dates, taken as LD 1, the same pattern of relative positions of Abd / smdt / wAgj (see 'Avg.LD' rows) is observed: Abd / Abd + 14 / Abd + 16, where Abd varies from 1.36 to 1.96”
    Quote in the paperSubstantial claim
  • Findingown data

    The three-day interval between smdt and wAgj from pBerlin 10165 turns out to be inconsistent with the rest of the data.

    “firstly, the three-day interval between smdt and wAgj from pBerlin 10165 turns out to be inconsistent with the rest of the data”
    Quote in the paperSubstantial claim
  • May combine two claims. 20
  • Classified as probably not a substantial claim. 1

  • May combine two claims.

    Findingown data

    Data from the Illahun archive evidence that there were two instances of the wAgj feast: a fixed one on a specific civil date and a movable one associated with a specific phase of the moon.

    “Data from the Illahun archive evidence that there were two instances of it: a fixed one, which fell on a specific civil date, and a movable one associated with a specific phase of the moon.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    Two different instances of wAgj are recorded in the Illahun archive: a civil one, fixed on I Axt 17/18; and a lunar one, which fell on different civil days.

    “Two different instances 1 of it are recorded in the Illahun archive: a civil one, fixed on I Axt 17/18 2 ; and a lunar one, which fell on different civil days; therefore, it is often called 'movable'.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Borchardt 1935

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Krauss 1985

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Luft 1992

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Findingreasoning

    The dates from pBerlin 10003, pBerlin 10248 and pBerlin 10282 used by Luft to calculate psD(n)tjw are Abd originally and therefore they cannot be used.

    “The dates from pBerlin 10003, pBerlin 10248 and pBerlin 10282 used by Luft to calculate psD(n)tjw are Abd originally and therefore they cannot be used (rule 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The Abdsmdt pair from pBerlin 10282b shows significant inconsistency and should be excluded.

    “The Abdsmdt pair from pBerlin 10282b shows significant inconsistency 9 and should be excluded (rule 2).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Depuydt 1997, 150

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Depuydt 2000, 179 source

  • May combine two claims.

    Findingown data

    Analysis of the lists of lunar days from the Ptolemaic Period reveals the erroneous position of one of the days; when it is set to the proper position, the symmetry of the phases relative to the day of full moon improves.

    “Analysis of the lists of lunar days from the Ptolemaic Period also reveals the erroneous position of one of the days; when it is set to the proper position, the symmetry of the phases relative to the day of full moon improves.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    If Table 5 is recalculated assuming Abd = LD 1, then wAgj falls on LD 17 (16.85); psD(n)tjw on LD 30 (29.91); and smdt/mDdj-nt on LD 15 (14.96), as indicated by its name.

    “If we recalculate Table 5, assuming Abd = LD 1, then wAgj falls on LD 17 (16.85);psD(n)tjw -on LD 30 (29.91); and smdt/mDdj-nt -on LD 15 (14.96), as indicated by its name.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Two instances of the unknown phase, sjAw (LD 14, LD 17), are not symmetrical with respect to the full moon: they are one and two days apart from it.

    “two instances of the unknown phase, sjAw (LD 14, LD 17), are not symmetrical with respect to the full moon: they are one and two days apart from it.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The numbering of the days of the lunar month, starting from the intercalary day, does not make sense, while the numbering from the first day of the new crescent visibility, Abd, is natural.

    “Obviously, the numbering of the days of the lunar month, starting from the intercalary day, does not make sense, while the numbering from the first day of the new crescent visibility, Abd, is, on the contrary, natural 18 .”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Days of the lunar month had names, some of which denote the phase of the moon: Abd - 'new crescent day'; dnjt - 'first/last quarter day'; while some others contain a numeral corresponding to the ordinal number of the lunar day: snt - '6th day'; smdt/mDdj-nt - '15th day', 'day of full moon'.

    “Days of the lunar month (LM) had names, some of which denote the phase of the moon: Abd -'new crescent day'; dnjt -'first/last quarter day'; while some others contain a numeral corresponding to the ordinal number of the lunar day (LD): snt -'6 th day'; smdt/mDdj-nt 3 -'15 th day', 'day of full moon' [Parker 1950, 11-12, §36-41].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Parker 1950, 11-12, §36-41

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    The method used by Luft to find the lunar day number is to calculate the distance between LD 1, psD(n)tjw, and the sought phase/event.

    “The method used by Luft [1992, 201;1994, 40-41] to find the lu-nar day number is to calculate the distance between LD 1, psD(n)tjw, and the sought phase/event.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Luft 1992, 201;1994, 40-41

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationown data

    Aggregation of the Illahun lunar dates into a 'date net' indicates that the disagreement is due both to peculiarities of the datasets of previous studies and to incorrect numeration of lunar days in Parker's list.

    “The aggregation of the Illahun lunar dates into a 'date net' indicates that the disagreement is due both to peculiarities of the datasets of previous studies and to the incorrect numeration of lunar days in Parker's list, which has been the standard for more than 70 years.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Parker 1950

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationown data

    Therefore the full moon occurs at both LD 15 and LD 16, and wAgj two days after it.

    “therefore the full moon occurs at both LD 15 and LD 16, and wAgj two days after it, respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    With this scheme, the new crescent always fell on Abd; psD(n)tjw functioned as an intercalary day.

    “With this scheme, the new crescent always fell on Abd; psD(n)tjw functioned as an intercalary day 17”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The calculation of the distance between phases assumes a known fixed interval between phases, and this is not always true.

    “the calculation assumes a known fixed interval between phases, and this is not always true”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Parker 1950, 4, §11

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationown data

    If psD(n)tjw is taken as the reference point, then the same phase is distributed between two adjacent days of the lunar cycle, and if Abd is the reference point, then the phase falls on the same day.

    “The discovered pattern indicates that if psD(n)tjw is taken as the reference point, then the same phase is distributed between two adjacent days of the lunar cycle, and if Abd is the reference point, then the phase falls on the same day.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    In the first case (pBerlin 10016), the movable wAgj falls on LD 17 (= 15 + 2), and in the second (pBerlin 10165), on LD 18 (= 15 + 3).

    “Thus, in the first case, the feast falls on LD 17 (= 15 + 2), and in the second, on LD 18 (= 15 + 3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    This numbering explains the temple service month intervals and the absence of psD(n)tjw in early private feast lists; the month-feast, Abd, coincides with the real beginning of the corresponding month, and the other phases are not delayed relative to the corresponding days.

    “Moreover, this numbering explains the temple service month intervals 19 and the absence of psD(n)tjw in early private feast lists 20 [Krauss 2006a, 386]; the month-feast, Abd, turns out to coincide with the real beginning of the corresponding month, and not with its second (or even third) day; the other phases are not delayed relative to the corresponding days, as in Parker's scheme [1950, 14, Fig”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Krauss 2006a, 386

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    In the corrected list, mspr is accompanied by mspr 2-nw, creating the mspr-sequence; smdt is symmetrically surrounded by two sjAw; the interval between quarters is normalized.

    “Now mspr is accompanied by mspr 2-nw, creating the mspr-sequence; smdt is symmetrically surrounded by two sjAw, in which it is easy to recognize the pre-and post-full moon phases; the interval between quarters is also normalized 22 .”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    psD(n)tjw was an unnumbered intercalary day and headed the lunar month due to the fact that intercalary days were regarded by the Egyptians as Hrjw days, 'which are upon/higher [time unit]'.

    “psD(n)tjw was an unnumbered intercalary day and headed the lunar month due to the fact that intercalary days were regarded by the Egyptians as Hrjw days, 'which are upon/higher [time unit]'”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Erman and Grapow 1929 (Wb. III), 133

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    The list of lunar days was corrupted sometime after the Middle Kingdom: mspr 2-nw, presumably as a result of the omission, was moved down to the position in which it appears in the lists of the Ptolemaic temples.

    “the list of lunar days was corrupted sometime after the Middle Kingdom: mspr 2-nw, presumably as a result of the omission, was moved down to the position in which it appears in the lists of the Ptolemaic temples 26 .”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Brugsch 1883, 45-48

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    The list has an element with a similar name, mspr, so putting them side by side results in a sequence of mspr, mspr 2-nw being the first and second 'rib' days.

    “The list has an element with a similar name, mspr, so putting them side by side results in a sequence of mspr, mspr 2-nw being the first and second 'rib' days 21 .”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Borchardt 1935, 37, n. 2

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Parker 1950, 71, n. 42

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

21 of 21

  • The paper relies on this without support.

    A synodic month averages 29.53059 days (varies from 29.25 to 29.83 days).

    “However, we know that a synodic month averages 29.53059 days (varies from 29.25 to 29.83 days)”
1 of 1

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Abd dataset includes a deviation outside its stated consistency limit

    Minor

    Table 2 includes an Abd date pair with a deviation of 1.00 day (about 1.004 days from the printed ΔLM), yet the paper says the dataset passes its consistency check. Its stated rule requires deviations of less than one day.

1 of 1

Cites

Flagged first, then by citations

Research works printed but not linked: 15

  1. Bárta W. (1981), "Der ägyptische Mondkalender und seine Schaltregulierung", Göttinger Miszellen. Beiträge zur ägyptologischen Diskussion, Hft. 47, pp. 7-13.
  2. Depuydt L. (1998), "The Hieroglyphic Representation of the Moon's Absence (PsDntyw)", in Lesko L. (ed.), Ancient Egyptian and Mediterranean Studies in Memory of W. A. Ward, Providence, pp. 71-89.
  3. Hughes G. (1958), "The Sixth Day of the Lunar Month and the Demotic Word for 'Cult Guild' ", Mitteilungen des Deutschen Archäologischen Instituts, Abteilung Kairo, Bd. 16, pp. 147-60.
  4. Krauss R. (1994b), "Fällt im Illahun-Archiv der 15. Mondmonatstag auf den 16. Mondmonatstag?", Göttinger Miszellen. Beiträge zur ägyptologischen Diskussion, Hft. 138, pp. 81-92.
  5. Krauss R. (2021), "The assumed moveable wAgj feast in the Raneferef archive", Göttinger Miszellen. Beiträge zur ägyptologischen Diskussion, Hft. 263, pp. 91-6.
  6. Luft U. (1994), "The Date of the WAgy Feast: Considerations on the Chronology of the Old Kingdom", in Spalinger A. (ed.), Revolutions in Time: Studies in Ancient Egyptian Calendars, Varia Aegyptiaca Supplements 6, Van Siclen Books, San Antonio, pp. 39-44.
  7. O'Mara P. (1984a), "Some Lunar Dates from the Old Kingdom in Egypt", Studies in the Structural Archaeology of Ancient Egypt, Vol. 3, No. 1, Paulette Publishing, La Canada.
  8. O'Mara P. (1984b), "Some Indirect Sothic and Lunar Dates from the Late Middle Kingdom in Egypt", Studies in the Structural Archaeology of Ancient Egypt, Vol. 3, No. 2, Paulette Publishing, La Canada.
  9. Parker R. (1950), The Calendars of Ancient Egypt, Studies on Ancient Oriental Civilization, Vol. 26, Chicago.
  10. Parker R. (1971), "The Calendars and Chronology", in Harris J. (ed.), The Legacy of Egypt, Clarendon, Oxford, pp. 13-26.
  11. Posener-Kriéger P. (1986), "Wag-Fest", in Helck W. and Westendorf W. (eds), Lexikon der Ägyptologie, Vol. 6, Harrassowitz, Wiesbaden, pp. 1135-9.
  12. Spalinger A. (1994), "Thoth and the Calendars", in Spalinger A. (ed.), Revolutions in Time: Studies in Ancient Egyptian Calendars, Varia Aegyptiaca Supplements, 6, Van Siclen Books, San Antonio, pp. 45-60.
  13. Spalinger A. (1995), "Notes on the Ancient Egyptian Calendars", Orientalia, T. 64, No. 2, pp. 17-32.
  14. Spalinger A. (2013), "Further Thoughts on the Feast of WAgj", Études et Travaux, T. XXVI, pp. 616-24.
  15. Winter E. (1951), Das ägyptische Wag-Fest, PhD Thesis, Vienna.

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Authors
Puchkov, A.
Venue
The Oriental Studies
Publisher
National Academy of Sciences of Ukraine (Co. LTD Ukrinformnauka) (Publications)
Published
2023-12-30
Volume
2023
Issue
92
ISSN
  • 1682-671X (ISSN-L)
  • 2415-8712
DOI
10.15407/skhodoznavstvo2023.92.093
OpenAlex
W4389836296
Semantic Scholar
27ebcec80802b256dfff07cbb2391d0bd45071b1
Cited by
1
References
22
Citations by year
2024: 1
FWCI
1.03
Type
journal article
Language
en
Open access
Licence
cc-by-nc
Locations
The Oriental Studies (publishedVersion, cc-by-nc)
Funders
University of Oxford
Topics
  • Social Sciences › Arts and Humanities › Archeology › Ancient Egypt and Archaeology
  • Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Historical Astronomy and Related Studies
  • Social Sciences › Anthropology › Classical Antiquity Studies
Keywords
lunar day, lunar phases, Ptolemaic period, Egyptian calendar

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