rdate displays and sets the local date and time from the host name or address given as the argument. It uses the RFC 868 protocol which is usually implemented as a built-in service of
inetd(8).
Available options:
-p
Do not set, just print the remote time
-s
Do not print the time.
-a
Use the
adjtime(2) call to gradually skew the local time to the remote time rather than just hopping.