Hi Holgar Isenberg,
I am not a great fan of the Sothic Cycle as it doesn't seem to work for astronomers when you check the dates, Sirius is very high in the sky at sunrise, so is open to criticism, but an Egyptian New Year was calculated on 20th July 139AD, and as the Sothic civil year is 1461 years, this couldn't have fallen during when Cleopatra was alive, thus she couldn't have aligned the Temple of Hathor in this way, however there are other choices like Thebes and Aswan, so throw the dice and choose!

[en.wikipedia.org]

Some Roman politicians wanted the Vernal Equinox to be the start of the year, others wanted the date when roman consuls changed office, and from 153BC, this is when this happened on 1st January, link below:-

[en.wikipedia.org]

Actually the Vernal Eqinox was set to 25th March and and the Winter Solstice was set at 25th December, oops! The reason we now have an earlier date is the days taken out for the Gregorian Calendar were 10 days and didn't go back to the start of the Julian Calendar in 45BC.

So you may think Caesar aligned Sirius to 1st January but this isn't true, as 46BC was the "Year of Confusion" being 445 days long, so within reason they were aligning dates to fall where they wanted, i can see Sosigenes and Cleopatra may have schemed and plotted how this would fall out!



Edited 2 time(s). Last edit at 10/11/2022 05:09AM by Archaeoastronomer.