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Telephone Time-of-Day Service

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 or voice over IP networks are used, the delays can be as large as 150 ms. In the very rare instances when the telephone connection is made by satellite, the time is delayed by more than 250 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 time-of-day service is used to synchronize clocks and watches and for the calibration of stopwatches and timers. It receives about 1,000 calls per day.

Outages

Date MJD Began (UTC) Ended (UTC)
23 September 2021 59480   1209
22 September 2021 59479 2053  
24 May 2021 59358   2100
22 May 2021 59356 1730  

Contacts

Created September 24, 2009, Updated September 23, 2021