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rtc(1m) [netbsd man page]

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)

Check Out this Related Man Page

zdump(1M)						  System Administration Commands						 zdump(1M)

NAME

       zdump - time zone dumper

SYNOPSIS

       zdump [-v] [-c cutoffyear] [zonename...]

DESCRIPTION

       The  zdump  command  prints the current time for each time zone (zonename) listed on the command line.  Specify zonename as the name of the
       time zone database file relative to /usr/share/lib/zoneinfo.

       Specifying an invalid time zone (zonename) to  zdump does not return an error,  rather  zdump uses GMT. This is consistent with the  behav-
       ior of the library calls; zdump reflects the same behavior of the time routines in libc. See  ctime(3C) and mktime(3C).

OPTIONS

       The following options are supported:

       -v	       Displays  the  entire  contents	of  the  time zone database file for zonename. Prints the time at the lowest possible time
		       value; the time one day after the lowest possible time value; the times both one second before and exactly at each time	at
		       which  the rules for computing local time change; the time at the highest possible time value; and the time at one day less
		       than the highest possible time value. See  mktime(3C) and  ctime(3C) for information regarding time  value  (time_t).  Each
		       line of output ends with isdst=1 if the given time is Daylight Saving Time, or isdst=0 otherwise.

       -c cutoffyear   Cuts off the verbose output near the start of the year cutoffyear.

EXIT STATUS

       The following exit values are returned:

       0	Successful completion.

       1	An error occurred.

FILES

       /usr/share/lib/zoneinfo	       Standard zone information directory

ATTRIBUTES

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

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

SEE ALSO

       zic(1M), ctime(3C), mktime(3C), attributes(5), environ(5)

SunOS 5.10							    19 May 1997 							 zdump(1M)
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