smdt

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egyptian: smdt

Definition

smdt (Egyptian smdt, "Half-Month Day") is the Egyptian name for the fifteenth day of the schematic lunar month — the day the full moon was most likely to fall, midway between first quarter (day 7, dnyt) and last quarter (day 23, dnyt II). It is one of the lunar days the Egyptians clearly singled out, alongside psḏntyw (LD1) and Abd (LD2), and it is the basis of the 12 monthly full-moon festivals attached to the civil calendar.

In Tradition

Egyptologists — Parker, Clagett, and Belmonte-Lull — read smdt as the Egyptian marker for the full moon, lunar day 15, the day that gave the month its mid-point liturgy. The 12 monthly first-crescent festivals (Abd) and the 12 monthly full-moon festivals (smdt) appear as a paired set in the Khnumhotep II list at Beni Hassan (12th Dynasty). At Medinet Habu, smdt is the last Feast of the Sky kept in each month before the count rolls forward.

In Practice

smdt anchors the mid-month full-moon observance within the schematic Egyptian run of named lunar days. From its protective god the feast also bears the name "Feast of the god Irmawa" (Clagett, Document III.5, Fig. III.91a, lower column 15). The Medinet Habu calendar (Document III.5) records smdt as the final Feast of the Sky in each month, since the festivals of LD29 and LD30 were set out before the next month's festival cycle began. Pairing a monthly Abd (first-crescent) feast with a monthly smdt (full-moon) feast — a 12 × 2 = 24 monthly lunar festivals fixed to the 365-day civil year — shows how Egyptian worship grafted moon-based markers onto the civil calendar without making the civil months themselves lunar. Egyptologists use the appearance of smdt to spot where temple ritual programs are running a lunar-and-civil double calendar.

Historical Origin

smdt is attested in Old Kingdom offering-formulas and Middle Kingdom tomb inscriptions (the Khnumhotep II list at Beni Hassan, 12th Dynasty) and is listed in the Medinet Habu calendar (Document III.5 in Clagett). The term is treated in Parker, Calendars of Ancient Egypt (1950); Clagett, Ancient Egyptian Science Vol II (1995); and Belmonte and Lull, In Search of Cosmic Order (2018).

Further Reading

  • Marshall Clagett, Ancient Egyptian Science, Volume II: Calendars, Clocks, and Astronomy
  • Juan Antonio Belmonte & José Lull, In Search of Cosmic Order: Selected Essays on Egyptian Archaeoastronomy