Ancient Egyptian Calendar

The calculator converts an Ancient Egyptian date to Gregorian date and vice versa.

The ancient Egyptian calendar is a 365 days solar calendar. The calendar year consists of 3 seasons; each season has 4 months, each month has 3 decades (weeks) of 10 days each. Every year ends with additional 5 days (epagomenal days), which gives 365 days in total. There were no leap years to make the calendar in sync with the tropical year, so the calendar loses one solar day every four years. There was no single date in the past from which ancient Egyptians started to keep years; instead, the years count restarted each time a new pharaoh began his reign. To align the Egyptian calendar with the contemporary calendar, we must know the pharaohs' accession year. The calculators below use Ptolemy canon of kings, which contains pharaoh regnal periods starting from Babylonian king Nabonassar (747 BCE) up to Roman Aelius Antoninus (161 CE)1. Assuming the new year day of Nabonassar's first reign year as of Feb 26th 747 BCE (Julian)2, we can calculate Gregorian dates corresponding to ancient Egyptian ones.
This calculator converts an ancient Egyptian date to a Gregorian date.

PLANETCALC, Ancient Egyptian date to Gregorian date

Ancient Egyptian date to Gregorian date


The calculator below converts a Gregorian date to an Ancient Egyptian date.

PLANETCALC, Gregorian date to Ancient Egyptian date

Gregorian date to Ancient Egyptian date

Month in season
Month name

The calculators use algorithms from the Calendrical Calculations book by Dershowitz and Reingold3.

The ancient Egyptian calendar summary

Calendar type fixed
Place Egypt
Days in a year 365
Effective date about 25th century BCE
End date 1st century CE (Egypt), used by medieval astronomers
Epoch Vary. The years' count was restarted when a new pharaoh began his reign.
Month count 13
Days in a week 10
Days in a year 365
Days in a month 30, 5
Leap year none
Previous calendar Egyptian lunar calendar
Next calendar Coptic calendar


Season # Season name Months Days
1 Akhet 4 120
2 Peret 4 120
3 Shemu 4 120
Epagomenal Days 0 5

Month names

Month # Month name Another name Days
1 I Akhet Thoth 30
2 II Akhet Phaophi 30
3 III Akhet Athyr 30
4 IV Akhet Choiak 30
5 I Peret Tybi 30
6 II Peret Mechir 30
7 III Peret Phamenoth 30
8 IV Peret Pharmuthi 30
9 I Shemu Pachons 30
10 II Shemu Payni 30
11 III Shemu Epiphi 30
12 IV Shemu Mesore 30
13 Epagomenal Days - 5

  1. Ptolemy's Almagest, translated and annotated by G.J. Toomer 

  2. O. Neugebauer, A history of ancient Mathematical Astronomy 

  3. N.Dershowitz, E.M. Reingold Calendrical Calculations Third edition. 

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PLANETCALC, Ancient Egyptian Calendar