I don't think the varying hour-length would apply, as there are too many complications with it for 'stellar-rotation' and what the decans do: every temple and priest would be up in arms about what they know; and every labourer would want shorter hours for the same pay as longer hours.

If you go for varying hour-length, then you have to include latitudes for the same hour-length no matter what time of year it is., just as long as the sun is directly overhead. As Earth has a tilt of 23.5 deg at the mo, and a range of about 2 or so degs, then you might be better checking out 24 as degrees and hours for a certain period of time in history...but we may have to include the circle and degrees: did the ancients divide their attention between 360 and 720 because it was necessary to do so?

That would mean a tilt of 12deg on the one hand, and 24 on the other...hmm...potential but I'm not sure...