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Telephone Time Service (TTS)

The Telephone Time Service is a dial-in service where an user with a computer and modem can get a machine readable time code over the telephone network. This time code, which is suitable for the automatic setting of a wide range of equipment and computer systems, is generated continuously under the control of the national standard for time. The service is available at no cost other than the initial equipment cost and the cost of the telephone call.

In line with the current International Telecommunication Union (ITU) recommendations, the TTS transmits Universal Co-ordinated Time (UTC) as kept at NMISA in Pretoria.

The TTS can be access on the following two telephone numbers: +27 12 349 1576/7. The best accuracy is obtained with older modems where the internal delays are fixed. Under such ideal situations, and assuming the user equipment (or computer) has a good enough timing resolution, an uncertainty of 1 millisecond can be obtained.

Note: Currently only one TTS server is still running due to hardware failures. NMISA will not fix the system, unless motivations are received, in writing, stating why the service must be continued.

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(c) 2007,2008 National Metrology Institute of South Africa