1rtc(1M)                 System Administration Commands                 rtc(1M)
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NAME

6       rtc - provide all real-time clock and GMT-lag management
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SYNOPSIS

9       /usr/sbin/rtc [-c] [-z zone-name]
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DESCRIPTION

13       On  x86  systems,  the rtc command reconciles the difference in the way
14       that time is established between UNIX and MS-DOS systems. UNIX  systems
15       utilize  Greenwich  Mean Time (GMT), while MS-DOS systems utilize local
16       time.
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19       Without arguments, rtc displays  the  currently  configured  time  zone
20       string.  The currently configured time zone string is based on what was
21       last recorded by rtc-z zone-name.
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24       The rtc command is not normally run from a shell prompt; it  is  gener‐
25       ally  invoked  by  the  system. Commands such as date(1) and rdate(1M),
26       which are used to set the time on a system, invoke /usr/sbin/rtc -c  to
27       ensure that daylight savings time (DST) is corrected for properly.
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OPTIONS

30       -c              This  option  checks  for  DST and makes corrections if
31                       necessary. It is normally run once a day by a cron job.
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33                       If there is no RTC time zone or  /etc/rtc_config  file,
34                       this option will do nothing.
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37       -z zone-name    This  option,  which  is  normally run by the system at
38                       software installation time, is used to specify the time
39                       zone  in  which the RTC is to be maintained. It updates
40                       the configuration file /etc/rtc_config with the name of
41                       the  specified  zone  and  the current GMT lag for that
42                       zone. If there is an  existing  rtc_config  file,  this
43                       command  will update it. If not, this command will cre‐
44                       ate it.
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FILES

48       /etc/rtc_config    The data file used to record the time zone  and  GMT
49                          lag.    This   file   is   completely   managed   by
50                          /usr/sbin/rtc, and it is read by the kernel.
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ATTRIBUTES

54       See attributes(5) for descriptions of the following attributes:
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59       ┌─────────────────────────────┬─────────────────────────────┐
60       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
61       ├─────────────────────────────┼─────────────────────────────┤
62       │Architecture                 │x86                          │
63       ├─────────────────────────────┼─────────────────────────────┤
64       │Availability                 │SUNWcsu                      │
65       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

68       date(1), rdate(1M), attributes(5)
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72SunOS 5.11                        3 Oct 2003                           rtc(1M)
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