For those who don't know, the callsigns are because the audio used by the phone service is primarily used for broadcast on shortwave / HF radio. If you're in t

For those who don't know, the callsigns are because the audio used by the phone service is primarily used for broadcast on shortwave / HF radio. If you're in the US and have a shortwave receiver you can usually pick up the time broadcasts on one of their frequencies any time of day. https://www.nist.gov/pml/time-and-frequency-division/radio-stations/wwv https://www.nist.gov/pml/time-and-frequency-division/radio-s...