Slightly unusual content for my blog but why not. One of my colleagues from Manchester University has some thoughts on the Sothic Cycle she wanted to share. Not having a blog herself I offered the services of mine, but these are her own thoughts. Feed back is especially welcome. Copyright Jean Greyling
THE SOTHIC CYCLE
For thousands of years the Egyptians used two calendars for record-keeping. One was an official calendar used by the civil service, and the other was a temple calendar used by the priesthood.
The official or civil calendar was a solar one with 365 days, in 12 months of 30 days each with an extra 5 days added on. It did not have the additional quarter of a day which we regulate by having a leap year every 4 years.
The religious or temple calendar was not solar but Sothic, that is a calendar governed by the star Sirius. (To the Egyptians Sirius was Sorpet or Sopdet and hence to the Greeks Sothis.) It did include the extra quarter day, and its year was 365 : 25 days.
The marker for the Sothic calendar was the heliacal – just before dawn – rising of Sirius. At one point in each cycle, just before dawn Sirius rose above the horizon in a direct line with the sun and the two calendars, solar and Sothic, synchronised.
For reasons that are clear to astronomers but not to many who try to explain them, and highly complex, to do with the different lengths of time of the earth’s rotation on its axis, its orbit round the sun, the precession of the equinoxes, and the apparent orbit of Sirius, Sothis rises above the horizon a little under four minutes earlier each day.
The result is that the two calendars drift apart by 6 hours, a quarter of a day, each year. They are thus apart by 1 day every 4 years, so 5 days after 20 years, 25 days in a century, 250 days in a millennium, and a year apart after 1460/61 years.
So the Sothic (or Siriac) calendar of the priesthood and the solar calendar of the civil bureaucracy coincide only once in every 1460 Sothic and 1461 solar years.
But they can APPEAR to be only one year apart.
* * *
Scope for confusing historians now?
All civil service, that is official and Pharaonic, records were dated by the solar calendar, and all temple ones by the Sothic calendar.
Not for nothing is the civil or solar year also known as the ‘vague’ year. (From ‘annus vagus’ or ‘wandering year’.*)
Where an event is recorded in both civil and temple records, it may appear to be only, tiresomely, a few months apart. (Ohhhh .. . . careless clerks.) BUT the records may actually be of two events hundreds of years apart.
An example in our own era – postulating that Britain’s Prince William becomes King William V – might be a reference in two sets of records, one dated by a solar calendar and the other by a Sothic one, to ‘the coronation of King William’.
William l became king of England in 1066 CE, William V is likely to be crowned nearly 1000 years – or a mere eight months of ‘calendar drift’? – later.
Lucie Lamy, Egyptian Mysteries pub. Thames and Hudson 1981
E.G. Richards, Mapping Time pub Oxford Univ. Press 1998
David Ewing Duncan, The Calendar, Fourth Estate 1998
pp 22- 3
George Hart, Egyptian Gods and Goddesses, Routledge 1986
For the scope for confusion and scholarly debate arising:
David Rohl, A Test of Time, pub Arrow/Century 1995
pp 146-53, 157, 492
• Richards, op cit p 153
I’ve two questions arising –
Have I understood the Sothic Cycle correctly? and
Is my example in the last two paragraphs a valid way to interpret and apply the Sothic calendar?
There may be other questions I don’t know to ask – all comments very welcome.