Epagomenal Days

Definition

The epagomenal days are the five extra days tacked onto the Egyptian civil year — twelve 30-day months — to bring it up to 365. The Egyptians called them heriu renpet ("those upon the year") or 5 Hryw rnpt ("Five above the Year"). They sit outside the three seasons of Akhet, Peret, and Shemu. A sixth, leap, epagomenal day was decreed by Ptolemy III's Decree of Canopus in 238 BCE, though it didn't hold then; it was finally instituted under Augustus, after 30 BCE.

In Tradition

In the Egyptian civil-calendar tradition the five epagomenal days are the birthdays of the gods — by the canonical reckoning, the births of Osiris, Horus the Elder, Seth, Isis, and Nephthys. In Egyptian hemerology — the practice of marking days as favourable or not — these five carry a heightened ritual charge, calling for observances and prohibitions, and that charge is attested across pharaonic and Greco-Roman calendars.

In Practice

Egyptian astronomer-priests counted the five epagomenals to round out the 365-day civil year used through pharaonic and Greco-Roman timekeeping. Without a leap day, that year slipped about one day every four solar years against the Sothic year — the long drift behind the Sothic cycle that Censorinus describes. The five days were kept separate from the regular months on monumental and tomb feast-lists, were flagged in hemerological day-books with their own prescriptions, and served chronologists as the boundary segment between one civil year and the next. On the diagonal star clocks, a special set of triangle-decans (E1-E12) was held back to mark the night-hours during just these five days.

Historical Origin

The epagomenal days are attested in the Pyramid Texts of Pepi II (Section 1961a-b, late Old Kingdom, 6th Dynasty, c. 2200 BCE) and in the Annals of Neferirkare (5th Dynasty), and continue across the Middle Kingdom feast-list of Khnumhotep II at Beni Hasan, the Ramesside hemerologies, and Ptolemaic-Roman documents. Modern treatment: Parker, *Calendars of Ancient Egypt* (1950); Clagett, *Ancient Egyptian Science* Vol II (1995); Belmonte & Lull, *In Search of Cosmic Order* (2009).

Definition

In Tradition

In Practice

Historical Origin

Further Reading