OpenRdate or openrdate or 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 868 TCP protocol server, which is usually implemented as a built-in service of inetd(8), or an RFC 5905 protocol SNTP/NTP server. By default, rdate uses the RFC 868 TCP protocol.
OpenRdate supports IPv4 and IPv6 protocols.