With WWV and a older-style shortwave receiver, the public has the ability to 
set a stopwatch or similar device to sub-second accuracy. More importantly, a 
person who isn't a time lord can be reasonably certain they have accomplished 
this task correctly.

With any other device I can think of, there is a lot of computing equipment 
serving as an intermediary between the radio signal (or the internal clock set 
by NTP) and the time display. This intermediary computing consumes a 
non-obvious amount of time that non-time-lords are ill-equipped to evaluate. 
Therefore such devices cannot be relied upon to display time to sub-second 

Such unreliable devices include personal computers (whether Linux, MacOS, or 
Windows), consumer "atomic clocks", consumer GPS devices, cell phones, etc. A 
less obvious instance of an unreliable computer intermediary are some of the 
more recent short wave receivers which perform digital signal processing, which 
may occur on the RF signal, the intermediate signal, or the audio signal.

People with a practical need for sub-second accuracy are navigators and land 
surveyors obtaining azimuth measurements by observations of celestial bodies, 
among others.

The number of people who can make a formal statement that the time kept by a 
particular clock is traceable to national standards will be drastically 
reduced, because the number of people who have, and know how to use, a 
shortwave receiver is vastly greater than the number of people who have a clock 
steered to GPS, and are capable of making a formal statement about the accuracy 
of the GPS-steered clock.

WWV can also be played to the public to directly demonstrate to that polling 
places are being opened and closed at the correct times. Computer displays and 
cell phone displays may not be persuasive to the public due to the extensive 
publicity about Russian hacking and other illegal manipulation of computers and 
related services. I'm an election official. I wonder how it will go over if, 
during the 2020 US presidential election, I turn a voter away because the time 
to close the polls has just passed, and CHU is playing in the background.
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