rtc(1M)                                                   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 string is 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 corrections 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
                       the  RTC is to be maintained. It updates the configuration file /etc/rtc_config with the name of the specified zone and the
                       current GMT lag for that zone. If there is an existing 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 completely managed by /usr/sbin/rtc, and it is
                               read by the kernel.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE         |      ATTRIBUTE VALUE        |
       +-----------------------------+-----------------------------+
       |Architecture                 |x86                          |
       +-----------------------------+-----------------------------+
       |Availability                 |SUNWcsu                      |
       +-----------------------------+-----------------------------+

SEE ALSO

       date(1), rdate(1M), attributes(5)

SunOS 5.10                                                          3 Oct 2003                                                             rtc(1M)