Limitations of the rdate Command

Synchronizing the Date and Time From Another System in Managing Clock Synchronization in Oracle Solaris 11.4 describes the use of the rdate command.

The rdate command is considered to be obsolete and might be removed in a future release.

Use NTP rather than the rdate command to set the system date and time, see the ntpdate(8) and ntpd(8) man pages.

The rdate command is limited in the following ways:

• The rdate command uses a network protocol that represents time as an unsigned 32-bit number of seconds ranging from January 1, 1900 to February 7, 2036. The rdate command further restricts this range by not changing the system date to dates prior to December 13, 1983. To synchronize time for dates past the end of this range, use another method, such as NTP.
• The rdate command requires that the remote system with which you synchronize the date and time run the svc:/internet/time:default service. This service has been disabled by default since Solaris 10 3/05. To use the rdate command successfully, you must use the svcadm command to enable the svc:/internet/time:default service on the remote system.
• The rdate command can set the time only to the nearest whole number of seconds because time is represented as an integer.
• The rdate command does not account for network travel time, so if a packet is dropped and re-transmitted, the time returned might be off by several seconds.