ntpdate

ntpdate sets the local date and time by polling the Network Time Protocol (NTP) server(s) given as the server arguments to determine the correct time. It must be run as root on the local host. A number of samples are obtained from each of the servers specified and a subset of the NTP clock filter and selection algorithms are applied to select the best of these. Note that the accuracy and reliability of ntpdate depends on the number of servers, the number of polls each time it is run and the interval between runs.

Documentation

• man 8 'ntpdate' [EN]

Parameters

-4

Force DNS resolution of following host names on the command line to the IPv4 namespace.

-6

Force DNS resolution of following host names on the command line to the IPv6 namespace.

-q

Query only - don't set the clock.

-t TIMEOUT

Specify the maximum time waiting for a server response as the value TIMEOUT, in seconds and fraction.

-u

Direct ntpdate to use an unprivileged port or outgoing packets. This is most useful when behind a firewall that blocks incoming traffic to privileged ports, and you want to synchronize with hosts beyond the firewall.

-U USER

ntpdate process drops root privileges and changes USER.