rdate - set the system's date from a remote host
rdate [-46acnpsv] host
rdate displays and sets the local date and time from the
host name or address
given as the argument. The time source may be an RFC
868 TCP protocol
server, which is usually implemented as a built-in
inetd(8), or an RFC 2030 protocol SNTP/NTP server. By default, rdate uses
the RFC 868 TCP protocol.
The options are as follows:
-4 Forces rdate to use IPv4 addresses only.
-6 Forces rdate to use IPv6 addresses only.
-a Use the adjtime(2) call to gradually skew the local
time to the
remote time rather than just hopping.
-c Correct leap seconds. Sometimes required when synchronizing to
an NTP server. When synchronizing using the RFC 868
use this option only if the server does not correctly account for
leap seconds. You can determine if you need this
you sync against an NTP server (with this parameter)
check with a local radio controlled watch or
-n Use SNTP (RFC 2030) instead of the RFC 868 time protocol.
-p Do not set, just print the remote time.
-s Do not print the time.
-v Verbose output. Always show the adjustment.
/var/log/wtmp record of date resets and time changes
To get the legal time in Germany, set the /etc/localtime
/usr/share/zoneinfo/right/Europe/Berlin and issue the following command:
# rdate -ncv ptbtime1.ptb.de
The command of course assumes you have a working internet
DNS set up to connect to the server at
Physikalisch-Technische [Toc] [Back]
Bundesanstalt in Braunschweig, Germany.
To gradually adjust time once an hour after the first "step"
put the following line into root's crontab:
58 * * * * rdate -ncav ptbtime1.ptb.de | logger
date(1), adjtime(2), inetd(8), ntpd(8), timed(8)
OpenBSD 3.6 April 30, 1994
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