/usr/sbin/rdate [ -s ] [ -v ] [ network ]
The rdate command is invoked at boot time to reset the system date and time to the current network date and time. The rdate program sends a broadcast datagram packet on the specified network or on the system default network if no network is specified. The program will then wait two seconds for responses. After that time, the arithmetic median of the responses is taken.
In order for rdate to determine a network time, at least one of the running hosts on the network must be running the internet time service. Machines with their own battery-backed-up time-of-day clock may not desire to set time in this manner.
date(1) delim off