You act like mentioning priests (or shall we say, holy men) is some sort of surprise. Who do you think organized the construction of Newgrange?
You provided the evidence of Newgrange, and then you ask how could this be done with a lunar calendar?
So, do you believe Newgrange or do you disbelieve Newgrange? Newgrange was built by following the half year progression of Sunrises. How does this involve the moon?
While I have always maintained that the human eye alone would be challenged to perceive the differences in movement of the sunrise between the true Solstice and the following 3 days, it was you who first suggested it couldn’t be done by any means.
So I was delighted when you, as a skeptic, found a man-made construction that made it possible to identify the exact and specific day.
You ask: “I would agree that in the days before and after the solstice the sun “appears” to stop moving south, but how does that get you to exactly 3 days after the solstice?”
In order to build Newgrange, the architect would have to know exactly where the furthest south Sunrise occurred, right?
So… once we have established that, the attendants would then start to count the days before they could “see” or “measure” a sizable jump northward! Modern astronomy confirms that it is 3 days after “the most southerly Sunrise” occurred.
The etymology of the Solstice indicates the Romans knew there was a pause of some sort. Otherwise there would be no point in using the term “-stit” for “stand still”.
I’m not really clear on what position you think you are defending. Once we have proven that the ancients were able to design a tool that could tell them the exact day of the southern-most Sunrise, everything else falls from that accomplishment.