core: use the correct APIs to determine whether a dual timestamp is initialized

[thirdparty/systemd.git] / man / localtime.xml

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  Copyright 2010 Lennart Poettering
  Copyright 2012 Shawn Landden

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<refentry id="localtime">
  <refentryinfo>
    <title>localtime</title>
    <productname>systemd</productname>

    <authorgroup>
      <author>
        <contrib>Developer</contrib>
        <firstname>Lennart</firstname>
        <surname>Poettering</surname>
        <email>lennart@poettering.net</email>
      </author>
      <author>
        <contrib>Developer</contrib>
        <firstname>Shawn</firstname>
        <surname>Landden</surname>
        <email>shawnlandden@gmail.com</email>
      </author>
    </authorgroup>
  </refentryinfo>

  <refmeta>
    <refentrytitle>localtime</refentrytitle>
    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>localtime</refname>
    <refpurpose>Local timezone configuration file</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><filename>/etc/localtime</filename> -&gt; <filename>../usr/share/zoneinfo/…</filename></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>The <filename>/etc/localtime</filename> file configures the
    system-wide timezone of the local system that is used by
    applications for presentation to the user. It should be an
    absolute or relative symbolic link pointing to
    <filename>/usr/share/zoneinfo/</filename>, followed by a timezone
    identifier such as <literal>Europe/Berlin</literal> or
    <literal>Etc/UTC</literal>. The resulting link should lead to the
    corresponding binary
    <citerefentry project='man-pages'><refentrytitle>tzfile</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    timezone data for the configured timezone.</para>

    <para>Because the timezone identifier is extracted from the
    symlink target name of <filename>/etc/localtime</filename>, this
    file may not be a normal file or hardlink.</para>

    <para>The timezone may be overridden for individual programs by
    using the <varname>$TZ</varname> environment variable. See
    <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>

    <para>You may use
    <citerefentry><refentrytitle>timedatectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    to change the settings of this file from the command line during
    runtime. Use
    <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    to initialize the time zone on mounted (but not booted) system
    images.</para>
  </refsect1>

  <refsect1>
      <title>See Also</title>
      <para>
        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
        <citerefentry project='man-pages'><refentrytitle>tzset</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>timedatectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
        <citerefentry><refentrytitle>systemd-firstboot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
      </para>
  </refsect1>

</refentry>