1 '\" te
   2 .\" Copyright (c) 2003, Sun Microsystems, Inc. All Rights Reserved.
   3 .\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
   4 .\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
   5 .\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
   6 .TH RTC 1M "Oct 3, 2003"
   7 .SH NAME
   8 rtc \- provide all real-time clock and GMT-lag management
   9 .SH SYNOPSIS
  10 .LP
  11 .nf
  12 \fB/usr/sbin/rtc\fR [\fB-c\fR] [\fB-z\fR \fIzone-name\fR]
  13 .fi
  14 
  15 .SH DESCRIPTION
  16 .sp
  17 .LP
  18 On x86 systems, the \fBrtc\fR command reconciles the difference in the way that
  19 time is established between UNIX and MS-DOS systems. UNIX systems utilize
  20 Greenwich Mean Time (\fBGMT\fR), while \fBMS-DOS\fR systems utilize local time.
  21 .sp
  22 .LP
  23 Without arguments, \fBrtc\fR displays the currently configured time zone
  24 string. The currently configured time zone string is based on what was last
  25 recorded by \fBrtc\fR\fB-z\fR \fIzone-name\fR.
  26 .sp
  27 .LP
  28 The \fBrtc\fR command is not normally run from a shell prompt; it is generally
  29 invoked by the system. Commands such as \fBdate\fR(1) and \fBrdate\fR(1M),
  30 which are used to set the time on a system, invoke \fB/usr/sbin/rtc\fR \fB-c\fR
  31 to ensure that daylight savings time (\fBDST\fR) is corrected for properly.
  32 .SH OPTIONS
  33 .sp
  34 .ne 2
  35 .na
  36 \fB\fB-c\fR\fR
  37 .ad
  38 .RS 16n
  39 This option checks for \fBDST\fR and makes corrections if necessary. It is
  40 normally run once a day by a \fBcron\fR job.
  41 .sp
  42 If there is no \fBRTC\fR time zone or \fB/etc/rtc_config\fR file, this option
  43 will do nothing.
  44 .RE
  45 
  46 .sp
  47 .ne 2
  48 .na
  49 \fB\fB\fR\fB-z\fR\fB \fR\fIzone-name\fR\fR
  50 .ad
  51 .RS 16n
  52 This option, which is normally run by the system at software installation time,
  53 is used to specify the time zone in which the \fBRTC\fR is to be maintained. It
  54 updates the configuration file \fB/etc/rtc_config\fR with the name of the
  55 specified zone and the current \fBGMT\fR lag for that zone. If there is an
  56 existing \fBrtc_config\fR file, this command will update it. If not, this
  57 command will create it.
  58 .RE
  59 
  60 .SH FILES
  61 .sp
  62 .ne 2
  63 .na
  64 \fB\fB/etc/rtc_config\fR\fR
  65 .ad
  66 .RS 19n
  67 The data file used to record the time zone and \fBGMT\fR lag. This file is
  68 completely managed by \fB/usr/sbin/rtc\fR, and it is read by the kernel.
  69 .RE
  70 
  71 .SH ATTRIBUTES
  72 .sp
  73 .LP
  74 See \fBattributes\fR(5) for descriptions of the following attributes:
  75 .sp
  76 
  77 .sp
  78 .TS
  79 box;
  80 c | c
  81 l | l .
  82 ATTRIBUTE TYPE  ATTRIBUTE VALUE
  83 _
  84 Architecture    x86
  85 .TE
  86 
  87 .SH SEE ALSO
  88 .sp
  89 .LP
  90 \fBdate\fR(1), \fBrdate\fR(1M), \fBattributes\fR(5)