Interpretation of lighting of the pyramid faces

I have long thought the lighting of the faces of the pyramids was some sort of a timepiece that could be seen by many, even at a great distance. I used Google Earth to show the lighting as the day progressed and saw it was different for different times of the year. Finally, I bit the bullet and recorded the times that each face was fully lit and again when it started to darken. I did this for the 20^(th) of every month and graphed the results. I did not see what I expected to see, regarding a way to tell what time it was, but I did see something that may be more useful.

What it revealed is a fixed length of time (six hours) that could correspond to a workday. Work starts with a certain combination of lighting and finishes at a different combination of lighting. And this remains the same throughout the year. And it does this twice a day so people that can’t be there for the early shift could start later. In addition, the lighting also denotes four fixed points in a year that could be used to start counting days to know when to plant seeds. I have attached a paper that goes into more detail. This lighting is a fact that can be seen by anyone. This behavior is the result of the precise construction and orientation of pyramids. The question is whether they went through such effort to make the lighting useful?

https://docs.google.com/document/d/1cfjuYidReUSEnMo12sFDtXpNEb-s_SHT/edit?usp=drive_link&ouid=117576507177872891277&rtpof=true&sd=true