We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
One of the authors I've read (Velikovsky maybe?) suggested that at the dawn of civilization, Earth had a 360 day year with 12 equal 30 day months. So it was natural to divide a day and night into 12 hours each and a circle into 360 degrees. Some cataclysm supposedly knocked the Earth into its present 365 1/4 orbit.
Because a circle's radius strikes off exactly six divisions, and because the angle between divisions with the center as vertex can be easily halved and quartered, some multiple of six is very convenient for any measure related to the heavens.
It is my understanding that originally a day was measured from sundown one evening to the sundown the next day. Certainly that is how Jews measure days: the Sabbath begins at sundown Friday and ends at sundown Saturday. Also, the early settlers used that method of counting days.
One can see how 12 noon could easily be recognized as that would be when the sun is at its zenith. However, this is the only essentially non-fluctuating mark in a day, as daylight hours increase and decrease with the seasons. Noon comes around fairly precisely every 24 hours, so our modern age has evolved ways to count the hours irrespective of the amount of daylight we actually have.