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8980 BIOS clock is sometimes one hour fast
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: C Fraire <cfraire@me.com>
*** 1,74 ****
RTC(1M) Maintenance 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 |
- +---------------+-----------------+
-
SEE ALSO
! date(1), rdate(1M), attributes(5)
!
!
! October 3, 2003 RTC(1M)
--- 1,80 ----
RTC(1M) Maintenance Commands RTC(1M)
NAME
! rtc - provide all real-time clock and UTC-lag management
SYNOPSIS
! rtc [-csuvw] [-z zone-name]
DESCRIPTION
! The Real Time Clock (RTC) is the hardware device on x86 computers that
! maintains the date and time. The RTC is battery-powered, so that it
! keeps running when the computer is shut down. It can be set from the
! BIOS and also from the operating system running on the computer. The RTC
! has no setting for the time zone or for Daylight Saving Time (DST). It
! relies on the operating system for these facilities and for automatic
! changes between standard time and DST.
+ On x86 systems, the rtc command reconciles the difference in the way that
+ time is established between UNIX and Windows systems. The internal clock
+ on UNIX systems utilizes Universal Coordinated Time (UTC) while Windows
+ systems usually expect the RTC to run in local time, including DST
+ changes.
! Without arguments, rtc displays the currently configured time zone string
! for the RTC. 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 rtc -c to ensure that daylight
+ savings time (DST) is corrected for properly.
OPTIONS
! -c This option checks for DST and makes corrections to the RTC if
! necessary. It is normally run once a day by a cron(1M) job.
! If there is no RTC time zone or /etc/rtc_config file, this option
! will do nothing.
+ -s This option specifies that the RTC runs in local standard time
+ all year round. It is incompatible with Windows, but is
+ convenient if only one operating system is to be run on the
+ computer. The cron(1M) command is not necessary, and should not
+ be run.
! -u This option specifies that the RTC runs in UTC time. As a side
! effect, it sets the time zone in /etc/rtc_config to UTC. Windows
! can operate in UTC time, but requires a registry change to do so.
! The cron(1M) command is not necessary.
+ -v This option specifies that the RTC tracks local time, including
+ DST changes. This is the default. It accomodates Windows with
+ no changes. The cron(1M) command is necessary to change the RTC
+ when DST is in effect.
! -w This option does nothing. It is present for compatibility with
! Solaris 11.
+ -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 UTC lag for that zone. If there is an existing
+ /etc/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 UTC lag.
! This file is completely managed by rtc. At boot time,
! the kernel reads the UTC lag from this file, and uses it
! to set the system time.
+ ARCHITECTURE
+ x86
SEE ALSO
! date(1), cron(1M), rdate(1M), attributes(5)
! illumos January 31, 2018 illumos