zOwie Omega Discussion Forum

Folks,

Just want to make a comment about accuracy of setting watches via PC based time syncing programs. This is an area that I work in, and have some expertiese in.

Time sync programs utilize the SNTP (Simple Network Time Protocol) to sync a device to a master clock, normally an atomic clock. These programs were originally developed for astronomers and geologists, who must make accurate simultaenous readings of events or locations.

Unfortunately, as the Internet has gotten so busy in the past few years, the delays going through the Internet have increased greatly. This affects the accuracy of these settings.

The best way to get an accurate time is to call one of the government (in the US, the US Navy Time Service or the National Institute of Standards recordings) and to synchronize your watch to these, as the delay through the Public Switched Telephone Network (PSTN) is both short (never more than a few hundred milliseconds unless trans-oceanic calls are involved) and more importantly, consistent. The delay of data through the Internet is both longer and much more variable, because of the packet nature of the Internet.

If you wish to syncronize to an atomic clock via a time sync program, do two things to help reduce the amount of delay in the network:

1. Look through the list of sites, and choose the site that is closest to you.

2. Time sync when the Internet is least busy. In the USA, this is Sunday mornings. Sunday morning traffic is just a fraction of the trafic at busy time (roughly typically 5:00 to 7:00 PM Eastern Time).

Colin

: What time hack do you use when testing the
: accuracy of your watch?