As a community of mostly engineering-minded folks, I hope we can take this as a warning to not make our mission-critical systems depend on inputs that are merely convenient side-effects of third-party systems provided free of charge and without obligation. I mean, it doesn't matter how many people post comments here saying things like "50 Hz AC is more accurate than quartz crystal for timekeeping", the fact is that no external agency can take over the action of your quartz crystal and force your clocks to slow down or speed up, whether intentional or not, as an effect of their political actions.
If you want a free source of mostly-reliable oscillations, and it doesn't have any real impact if it falls out of sync, sure go ahead and use something like this. But in the case of time, if you want to sync a clock in Western Europe with something that is free and non-internet based, you're much better off using DCF77 [0], which is specifically designed to synchronize time and comes with specific uptime and quality promises. Still ultimately susceptible to political actions, of course, in extreme cases, but at least you know its primary purpose is to transmit time information, and it is in the control of only one (relatively) stable government as opposed to being subject to the unpredictable changes brought about by interactions between multiple interconnected systems.
DFC77 doesn't solve the same problem as using AC as an oscillator, of course, since you still need an oscillator to keep your clock going during the downtimes that are permitted to the radio signal.
[0] https://en.wikipedia.org/wiki/DCF77
If you want a free source of mostly-reliable oscillations, and it doesn't have any real impact if it falls out of sync, sure go ahead and use something like this. But in the case of time, if you want to sync a clock in Western Europe with something that is free and non-internet based, you're much better off using DCF77 [0], which is specifically designed to synchronize time and comes with specific uptime and quality promises. Still ultimately susceptible to political actions, of course, in extreme cases, but at least you know its primary purpose is to transmit time information, and it is in the control of only one (relatively) stable government as opposed to being subject to the unpredictable changes brought about by interactions between multiple interconnected systems.
DFC77 doesn't solve the same problem as using AC as an oscillator, of course, since you still need an oscillator to keep your clock going during the downtimes that are permitted to the radio signal.
[0] https://en.wikipedia.org/wiki/DCF77