1 | <?xml version="1.0" encoding="ISO-8859-1"?>
|
---|
2 | <!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN" "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
|
---|
3 | <!ENTITY % general-entities SYSTEM "../general.ent">
|
---|
4 | %general-entities;
|
---|
5 | ]>
|
---|
6 | <sect1 id="ch-scripts-setclock">
|
---|
7 | <title>Configuring the setclock Script</title>
|
---|
8 | <?dbhtml filename="setclock.html"?>
|
---|
9 |
|
---|
10 | <indexterm zone="ch-scripts-setclock">
|
---|
11 | <primary sortas="d-setclock">setclock</primary>
|
---|
12 | <secondary>configuring</secondary></indexterm>
|
---|
13 |
|
---|
14 | <para>The <command>setclock</command> script reads the time from the hardware clock,
|
---|
15 | also known as the BIOS or the Complementary Metal Oxide Semiconductor
|
---|
16 | (CMOS) clock. If the hardware clock is set to UTC, this script will convert the hardware clock's time to
|
---|
17 | the local time using the <filename>/etc/localtime</filename> file
|
---|
18 | (which tells the <command>hwclock</command> program which timezone the
|
---|
19 | user is in). There is no way to
|
---|
20 | detect whether or not the hardware clock is set to UTC time, so this
|
---|
21 | needs to be manually configured.</para>
|
---|
22 |
|
---|
23 | <para>If you cannot remember whether or not the hardware
|
---|
24 | clock is set to UTC time, find out by running
|
---|
25 | the <userinput>hwclock --localtime --show</userinput> command. This will tell
|
---|
26 | what the current time is according to the hardware clock. If this time
|
---|
27 | matches whatever your watch says, then the hardware clock is set to
|
---|
28 | local time. If the output from <command>hwclock</command> is not local
|
---|
29 | time, chances are it is set to UTC time. Verify this by adding or
|
---|
30 | subtracting the proper amount of hours for the timezone to this
|
---|
31 | <command>hwclock</command> time. For example, if you live in the MST
|
---|
32 | timezone, which is also known as GMT -0700, add seven hours to the local
|
---|
33 | time. Then, account for Daylight Savings Time, which requires
|
---|
34 | subtracting an hour (or only add six in the first place) during the summer
|
---|
35 | months.</para>
|
---|
36 |
|
---|
37 | <para>Change the value of the <envar>UTC</envar> variable below
|
---|
38 | to a value of <parameter>0</parameter> (zero) if the hardware clock
|
---|
39 | is <emphasis>not</emphasis> set to UTC time.</para>
|
---|
40 |
|
---|
41 | <para>Create a new file <filename>/etc/sysconfig/clock</filename> by running
|
---|
42 | the following:</para>
|
---|
43 |
|
---|
44 | <screen><userinput>cat > /etc/sysconfig/clock << "EOF"
|
---|
45 | <literal># Begin /etc/sysconfig/clock
|
---|
46 |
|
---|
47 | UTC=1
|
---|
48 |
|
---|
49 | # End /etc/sysconfig/clock</literal>
|
---|
50 | EOF</userinput></screen>
|
---|
51 |
|
---|
52 | <para>A good hint explaining how to deal with time on LFS is available
|
---|
53 | at <ulink url="&hints-root;time.txt"><phrase
|
---|
54 | condition="pdf">http://www.linuxfromscratch.org/
|
---|
55 | hints/downloads/files/time.txt</phrase></ulink>. It explains issues such as
|
---|
56 | time zones, UTC, and the <envar>TZ</envar> environment variable.</para>
|
---|
57 |
|
---|
58 | </sect1>
|
---|
59 |
|
---|