I think you are on to something. I found this article very interesting. Especially the part about two different clock, one for outside laborers and one for inside. Also mentions winding the clock with markers. The markers were the days of the week. The first marker was Sunday. Interesting that the day the clock started (12/7/17) was a Sunday.
https://www.monticello.org/site/jefferson/design-and-decor-great-clock