Time (physics): If all the clocks in the world stopped working for a few days, would we be able to… by Edward Bashaw
Answer by Edward Bashaw:
Yes. This is the Royal Observatiry at Greenwich where Greenwich mean time is determined. The time ball is on the right. It drops each day at 1pm, based on solar observations. It was done so ships leaving the ports around London could set their chronometers before leaving England
Before quartz clocks and atomic clocks, time was determined astronomically. While not as accurate as today's highly refined devices they were adequate for their role in celestial navigation. Watchmakers at the height of the watchmaking profession made observatory grade watches that were sent to observatories to certify their timekeeping prowess. Here is a detail from such a watch
So long as the stars kept moving, even if all man made devices stopped functioning for a week or a month, within a short time we could re-establish the current time structure using the same methods we used to put it together in the first place. The fact that we have detailed star charts and other pieces of information unavailable at earlier times, the reconstituting of apparent time would not be that difficult in a reasonable period of time as for the most part, in daily human activity (absent timing signals for cell phones and other electronic devices) most of our time concerns are relative to personal events "how long till dinner", "when will you be here", "are we there yet".
As has been said, "God created the day and the year, everything else was defined by man"