WWV and WWVH are standard time and frequency stations operated by the National Institute of Science and Technology (NIST) formerly known as the National Bureau of Standards. The stations operate on 2.5, 5, 10, 15 and 20 MHz. WWV operates from Fort Collins, CO and WWVH operates from Hawaii.
A broadcast station may occasionally rebroadcast the signals of WWV/WWVH. The signals must be rebroadcast live. You can't record it and play it back later. Also, the call letters of WWV and WWVH may not be broadcast. At the top of the hour, you will hear the phrase "National Institute of Science and Technology Time..", followed by a pause. At that pause is where you want to cut out.
The rules expect you to attribute the time signal as being from the NIST and no commercial sponsorship of the signal is permitted.
For more information, see §73.1207(d)(2).
