Index of Section 8 Manual Pages
|Interix / SUA||rdate.8||Interix / SUA
RDATE(8) System Manager's Manual RDATE(8)
rdate - set the system's date from a remote host
rdate [-46acnpsv] host
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 2030 protocol SNTP/NTP server. By default, rdate
uses the RFC 868 TCP protocol.
The options are as follows:
-4 Forces rdate to use IPv4 addresses only.
-6 Forces rdate to use IPv6 addresses only. (Not active on Interix.)
-a Use the adjtime(2) call to gradually skew the local time to the
remote time rather than just hopping. (Not currently active on
-c Correct leap seconds. Sometimes required when synchronizing to
an NTP server. When synchronizing using the RFC 868 protocol,
use this option only if the server does not correctly account for
leap seconds. You can determine if you need this parameter if
you sync against an NTP server (with this parameter) or (recom-
mended) check with a local radio controlled watch or phone ser-
-n Use SNTP (RFC 2030) instead of the RFC 868 time protocol.
-p Do not set, just print the remote time.
-s Do not print the time.
-v Verbose output. Always show the adjustment.
Users will need to have been granted the permission SE_SYSTEMTIME_PRIVI-
LEGE in order to adjust the time. Typically the Administrator account and
accounts in the Administrators group have this permission but it can be
granted to other accounts.
To get the legal time for your location ensure that the environement
variable TZ is set and issue the following command:
# rdate -cv swisstime.ethz.ch
The command of course assumes you have a working internet connection and
DNS set up to connect to the server at Integrated Systems Laboratory,
Swiss Fed. Inst. of Technology in Zurich, Switzerland. Of course this is
an example and servers will come into and go out of service, so you may
need to lookup a valid server.
To gradually adjust time once an hour after the first "step" adjustment,
put the following line into the local Administrator's crontab:
58 * * * * rdate -cv swisstime.ethz.ch | logger -t NTP
date(1), inetd(8), localtime(3), tzset(3)
Interix August 27, 2004 Interix