rdate —
set the system's date from a remote 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 5905
protocol SNTP/NTP server or an RFC 868 TCP protocol server, which is usually
implemented as a built-in service of
inetd(8). By default,
rdate uses the RFC 5905 SNTP/NTP 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. This should be used only when synchronizing to a
server which does not correctly account for leap seconds.
-n- Use SNTP (RFC 5905) instead of the RFC 868 time protocol. This is the
default. This protocol counts 32 bits of seconds from January 1, 1900 and
will rollover in March 2036.
-o- Use an RFC 868 TCP protocol server instead of SNTP. This protocol is
obsolete as it is not capable of representing dates past January 19, 2038
03:14:07 GMT.
-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