Well... and there's the electricity grid which can be used for timing needs accurate enough to a single second, and in Europe there's DCF77 [1] which can not ju

Well... and there's the electricity grid which can be used for timing needs accurate enough to a single second, and in Europe there's DCF77 [1] which can not just be used as a 2*10^-12 seconds-accurate timing standard but also a frequency standard. [1] https://de.wikipedia.org/wiki/DCF77 https://de.wikipedia.org/wiki/DCF77