Time signals can also be heard on shortwave radio or by phone.
"The audio portions of the WWV and WWVH broadcasts can also be heard by telephone.
The time announcements are normally delayed by less than 30 ms when using land lines from within the continental United States, and the stability (delay variation) is generally 1 ms.
When mobile phones are used, the delays are often more than 100 ms due to the multiple access methods used to share cell channels.
In rare instances when the telephone connection is made by satellite, the time is delayed by 250 to 500 ms.
To hear these broadcasts, dial (303) 499-7111 for WWV (Colorado), and (808) 335-4363 for WWVH (Hawaii). Callers are disconnected after 2 minutes. These are not toll-free numbers; callers outside the local calling area are charged for the call at regular long-distance rates.
The telephone service is very popular. The WWV number receives over 1 million calls per year, and the WWVH number receives more than 50,000."