taiclockd — announce the system's clock through TAICLOCK




taiclockd announces the local UNIX clock through the TAICLOCK protocol. It accepts TAICLOCK requests from hosts around the Internet, and responds with the system's current time.

Normally taiclockd is run via a server program such as udp-socket-listen to listen for TAICLOCK queries from hosts around the Internet. It understands the LISTEN_PID and LISTEN_FDS environment variable convention for having an already-listening socket passed to it by such a program, and uses the last open file descriptor in the list that refers to a UDP/IPv4 socket. If no such open file descriptor is provided it falls back to opening its own UDP/IPv4 socket, bound to port 4014 of the IP address given by the value of the IP environment variable.

Do not run taiclockd if your system is tuned by xntpd. See Daniel J. Bernstein's UTC, TAI, and UNIX time paper for further discussion.


taiclockd does not need to run as root.


taiclockd was originally part of Daniel J. Bernstein's clockspeed toolset in 1998.


Original code and documentation by Daniel J. Bernstein. Documentation modernizations by Jonathan de Boyne Pollard.