"Another piece of non-textual evidence is the calendar. Because of their arithmetic backwardness, Greeks made a mess of the calendar they had earlier copied from Egypt like their gods. Acknowledging that mess Julius Caesar reformed the Roman calendar with great fanfare, though the net result only aggravated the mess about months (e.g. July has 31 days in honour of Julius, so August competitively has 31 days in honour of Augustus, and February is reduced to 28 or 29)! That (Julian) calendar was adopted as the Christian religious calendar in the 4th c Nicene council to fix the date of the Easter ritual, then the main church festival. However, even that "reformed" calendar had the wrong length of the year (as 365¼ days). That was a gross error even in comparison with 3rd c calendars from India. The gross error arose because the Roman system of numeration had no way to articulate fractions, except for simple fractions like half and quarter; therefore they were unable to state the true length of the year (but that wrong figure is what the colonially educated still learn!). This error (in the second place after the decimal point) naturally led to a noticeable slip in the date of Easter within a century. The church repeatedly tried to correct the error, but even the 5th c Hilarius reforms failed. The church controlled the Roman state then, and Hilarius was a pope, so the only possible reason for this persistent failure to fix the error in the date of the key religious ritual was this : basic knowledge of astronomy was unavailable in the Roman empire. Thus the non-textual evidence states the real hilarious story of Roman incompetence in astronomy, contrary to the tall tale of a Graeco-Roman Ptolemy who authored an advanced text on astronomy in the 2nd c. That is, neither "Claudius Ptolemy" nor advanced knowledge of astronomy existed anywhere in the Roman empire in the 5th c. Lack of accurate knowledge of so basic a parameter as the length of the year nails those false claims?"