[1] In the past, the Besançon Observatory participated in assessing and rating Swiss timepiece movements for accuracy.

From this need developed an accuracy testing regime involving various astronomical observatories.

The General Bulletin Order stated the testing criteria, and the actual performance of the movement.

The role of the observatories in assessing the accuracy of mechanical timepieces was instrumental in driving the mechanical watchmaking industry toward higher and higher levels of accuracy.

Accordingly, such chronometer certification ceased in the late 1960s and early 1970s with the advent of the quartz watch movement.