netdate linux command

netdate

netdate [options] [protocol] hostname

TCP/IP command. Set the system time according to the time provided by one of the hosts in the list hostname. netdate tries to ascertain which host is the most reliable source. When run by an unprivileged user, netdate reports the current time, without attempting to set the system clock. You may specify the protocol -- udp (the default) or tcp -- once, or several times for various hosts.

Options

-l time

The most reliable host is chosen from the list by sorting the hosts into groups based on the times they return when questioned. The first host from the largest group is then polled a second time. The differences between its time and the local host's time on each poll are recorded. These two differences are then compared. If the gap between them is greater than time (the default is five seconds), the host is rejected as inaccurate.

-v

Display the groups into which hosts are sorted.