A timekeeping mechanism of sufficient quality shared among the locations is also necessary right? Also the civilization would need to have their latitudinal ter

A timekeeping mechanism of sufficient quality shared among the locations is also necessary right? Also the civilization would need to have their latitudinal territory in alignment with the specific time of the transit. In 1663 Scottish mathematician James Gregory had suggested in his Optica Promota that observations of a transit of the planet Mercury, at widely spaced points on the surface of the Earth, could be used to calculate the solar parallax and hence the astronomical unit using triangulation. Aware of this, a young Edmond Halley made observations of such a transit on 28 October O.S. 1677 https://en.wikipedia.org/wiki/Transit_of_Venus#1761_and_1769 https://en.wikipedia.org/wiki/Transit_of_Venus#1761_and_1769