"Mike" <mike@lumieresimaginaire.com> wrote on Fri, 22 Jul 2016 at 22:21:08 +0200 in <bec8a6a992cdbd21bb47efe68a5797d8@lumieresimaginaire.com>: > You will also note from the NIST document and the NIST time server > address links, that the UT1 NTP service will not respond to > unregistered requests. NIST may or may not have opened the box > deliberately. I don't know, but if you wish to use the service > please at least contact Judah before doing so. It would be a shame > to have it going deaf. On June 28, Judah Levine and NIST announced via the IERS Message list that NIST's UT1 ntp-based time service would be open access beginning in July 2016. Announcement reproduced below. I found your email fairly confusing. --jhawk@mit.edu John Hawkinson Message-ID: <25948628.481467094028650.JavaMail.cmadmin@gsb50ml1.ffm.web> Date: Tue, 28 Jun 2016 08:07:08 +0200 From: <central_bureau@iers.org> To: <messages@iers.org> Subject: IERS Message No. 303: NIST UT1 Internet Time Service ************************************************************************ IERS Message No. 303 June 28, 2016 ************************************************************************ NIST UT1 Internet Time Service The Time and Frequency Division of NIST operates an Internet time server that transmits UT1 time in the Network Time Protocol (NTP) format. The server is synchronized to UTC(NIST) by a direct connection to a local cesium standard. The offset between UT1 and UTC is added to the reply to a query for the time. The time difference between UT1 and UTC is obtained from IERS Bulletin A, and the value used by the time server changes every day at 0 h UTC. The time step at 0 h UTC is generally about 1-2 ms. This time step is generally too small to be detected by most users. The accuracy of the time at the server is approximately 4 ms, and is determined by the uncertainty in the prediction of the difference UT1-UTC in the IERS Bulletin A. The accuracy of the time received by a user will usually be limited by the stability of the network delay from the user's system to the time server. The overall accuracy of the time as received by a user will generally be better than 10 ms, and will often be significantly better than this value. The name of the server is ut1-time.colorado.edu and its address is 128.138.140.50. The ut1 time service is currently restricted to users who register with NIST (by e-mail to Judah.levine [at] nist.gov), but it will be converted to open-access in July, 2016. The NIST is the US National Institute of Standards and Technology (http://www.nist.gov/). Questions or comments to Judah.Levine [at] nist.gov ************************************************************************ IERS Messages are edited and distributed by the IERS Central Bureau. If not stated otherwise, the IERS is only the distributor of the message and is not responsible for its content. To submit texts for distribution and to subscribe or unsubscribe, please write to <central_bureau@iers.org>. Archives: http://www.iers.org/Messages/ ************************************************************************