System Administration Commands rtc(1M)
NAME
rtc - provide all real-time clock and GMT-lag management
SYNOPSIS
/usr/sbin/rtc [-c] [-z zone-name]
DESCRIPTION
On x86 systems, the rtc command reconciles the difference in
the way that time is established between UNIX and MS-DOS
systems. UNIX systems utilize Greenwich Mean Time (GMT),while MS-DOS systems utilize local time.
Without arguments, rtc displays the currently configured
time zone string. The currently configured time zone stringis based on what was last recorded by rtc-z zone-name.
The rtc command is not normally run from a shell prompt; it
is generally invoked by the system. Commands such as date(1) and rdate(1M), which are used to set the time on a system,invoke /usr/sbin/rtc -c to ensure that daylight savings time
(DST) is corrected for properly. OPTIONS-c This option checks for DST and makes correc-
tions if necessary. It is normally run once a day by a cron job. If there is no RTC time zone or/etc/rtc_config file, this option will do
nothing.-z zone-name This option, which is normally run by the
system at software installation time, is used to specify the time zone in which theRTC is to be maintained. It updates the con-
figuration file /etc/rtc_config with the
name of the specified zone and the currentGMT lag for that zone. If there is an exist-
ing rtc_config file, this command will
update it. If not, this command will create it. FILES/etc/rtc_config The data file used to record the time
zone and GMT lag. This file is completelymanaged by /usr/sbin/rtc, and it is read
by the kernel.SunOS 5.11 Last change: 3 Oct 2003 1
System Administration Commands rtc(1M)
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Architecture | x86 ||_____________________________|_____________________________|
| Availability | SUNWcs ||_____________________________|_____________________________|
SEE ALSO
date(1), rdate(1M), attributes(5)SunOS 5.11 Last change: 3 Oct 2003 2