TL;DR: In brief
Egypt’s civil year had exactly 365 days: three seasons of four thirty-day months, plus five feast days outside the months. There was no leap day, so the calendar slid one day against the sun every four years — the “wandering year.” By luck of that slow drift, in Tutankhamun’s reign the named seasons happened to fall roughly where they belonged. The novels’ chapter headings use this calendar exactly as a Scribe would have written it.
Every chapter of the series is dated the way an Egyptian Scribe would have dated it: Regnal year 3, Second Month of Akhet, Day 15. This page explains what those words meant, how the Egyptian year actually worked, and why a calendar with no leap day spent most of Egyptian history quietly out of step with the seasons it was named for.
A Year Built From the River #
The Egyptian year did not begin with a solstice or an equinox. It began with water. Once a year the Nile rose, spilled over its banks, and buried the fields under fertile silt; everything else in Egyptian life was timed around that event. The civil calendar divided the year into three seasons named for the river’s rhythm: Akhet (Inundation), when the flood covered the land; Peret (Emergence), when the fields rose out of the water and were sown; and Shemu (Harvest), when the crops came in and the river shrank to its lowest.
Each season held four months, each month exactly thirty days, divided into three ten-day “weeks” — decans, as they are now called. Twelve months of thirty days makes 360 — so five extra days were added outside the months entirely: the Epagomenal Days, held to be the birthdays of Osiris, Horus, Set, Isis, and Nephthys. They were days of unease and festival at once, a small hinge of danger between one year and the next. Together: 365 days, every year, without exception.
The Wandering Year #
That “without exception” is the interesting part. The true solar year is about a quarter of a day longer than 365 days — the reason our own calendar inserts a leap day every four years. Egypt’s civil calendar never did. So every four years, the calendar slipped one full day against the sun, and against the river. The slippage was invisible in a lifetime — a couple of weeks in an old man’s memory — but relentless across centuries. New Year’s Day crept slowly through the real seasons, taking about 1,460 years to wander all the way around the year and come home again, a span modern scholars call the Sothic cycle.
The name comes from Sopdet — the star we call Sirius — whose reappearance in the dawn sky each year, after Seventy days of invisibility, was the traditional herald of the coming flood. Ideally, New Year’s Day and the rising of Sopdet coincided. Most of the time they did not: the calendar was simply elsewhere. For long stretches of Egyptian history, the month names were fossils — a farmer could live his whole life harvesting in the season called Inundation and think nothing of it, the way we think nothing of a ninth month named “seventh” (September) or a tenth named “eighth” (October).
Where the Series Sits #
By good fortune of the drift, the decade in which the series is Set — the reign of Tutankhamun, c. 1332–1323 BCE — falls in a stretch when the civil calendar stood in approximate alignment with the actual seasons. When a chapter heading in the novels says Second Month of Akhet, the flood really was on the land. In modern terms, the Inundation reached Egypt in high summer: Sopdet rose in the dawn sky around mid-July by our reckoning, with the river’s rise following through July and August, the sown fields of Peret spanning roughly November to March, and the harvest of Shemu running into the baking early summer, when the river fell to its lowest and the year turned again.
The alignment is approximate, and deliberately so — the drift never stops, and pinning ancient dates to modern months depends on which absolute chronology a scholar adopts. The series treats the correspondence the way its characters would have: the seasons are real events you can smell and wade through, not entries in an almanac.
Counting the Years #
Egypt had no running era — no equivalent of “2026.” Years were counted by reign: the count began anew at each king’s accession and died with him. A date was therefore always a political statement as much as a timestamp: Regnal Year 3 means the third year of this king — and in a decade with contested successions, whose year-count a Scribe used could say a great deal. A single wine-jar Docket relabelled from one king’s count to another’s is one of the quietest and most consequential pieces of evidence in the whole Amarna puzzle.
The Prologue and Chapter One of The Poisoner’s Throne take place shortly before Tutankhamun’s coronation, and so carry no Regnal year at all — his count had not yet begun. Every dated chapter after that follows the scribal formula: Regnal year, month of the season, day.
A note on grading: the shape of the calendar — 365 days, three seasons, the five Epagomenal Days, the quarter-day drift — is attested beyond doubt. Absolute dates such as c. 1332–1323 BCE, and the near-alignment of the named seasons with the real ones in Tutankhamun’s reign, depend on which chronology a scholar adopts and are given here on the standard reckoning.