NTP: The Network Time Protocol

Welcome to, home of the Network Time Protocol (NTP) project.

This page is home for the NTP software package, the official reference implementation of the NTP protocol. The NTP distribution is largely a volunteer effort: For a partial list of active developers, please see the contributors page. This web site, and all pages directly contained within, are in the public domain. Some portions of the page may be copyrighted by other authors. Please contact the webmaster with any questions regarding copyright. The NTP software distribution is copyrighted, as described in the NTP copyright page.

NTP is a protocol designed to synchronize the clocks of computers over a network. NTP version 3 is an internet draft standard, formalized in RFC 1305. NTP version 4 is a significant revision of the NTP standard, and is the current development version, but has not been formalized in an RFC. Simple NTP (SNTP) version 4 is described in RFC 2030.

New NTP users should read the Where-To-Start file included with the NTP distribution. Additional information is available on the documentation page. If you would like to find a server to get time from, please see the public NTP server list. If you would like to locate NTP software other than the reference distribution, please see the links page.

A list of NTP servers and reference clocks, ntp documentation, time and frequency standard stations, and time and frequency standard station transmission data is maintained at the Information on Time and Frequency Services page. Background information about NTP, along with briefings and a bibliography, are available at the Network Time Synchronization Project page.

To contact the NTP web maintainer or any of the NTP developer team, please see the contact page. Please direct comments and questions about the web site to the webmaster.