man/timedatectl.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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   8   Copyright 2012 Lennart Poettering
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  23
  24 <refentry id="timedatectl" conditional='ENABLE_TIMEDATED'
  25         xmlns:xi="http://www.w3.org/2001/XInclude">
  26
  27         <refentryinfo>
  28                 <title>timedatectl</title>
  29                 <productname>systemd</productname>
  30
  31                 <authorgroup>
  32                         <author>
  33                                 <contrib>Developer</contrib>
  34                                 <firstname>Lennart</firstname>
  35                                 <surname>Poettering</surname>
  36                                 <email>lennart@poettering.net</email>
  37                         </author>
  38                 </authorgroup>
  39         </refentryinfo>
  40
  41         <refmeta>
  42                 <refentrytitle>timedatectl</refentrytitle>
  43                 <manvolnum>1</manvolnum>
  44         </refmeta>
  45
  46         <refnamediv>
  47                 <refname>timedatectl</refname>
  48                 <refpurpose>Control the system time and date</refpurpose>
  49         </refnamediv>
  50
  51         <refsynopsisdiv>
  52                 <cmdsynopsis>
  53                         <command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>
  54                 </cmdsynopsis>
  55         </refsynopsisdiv>
  56
  57         <refsect1>
  58                 <title>Description</title>
  59
  60                 <para><command>timedatectl</command> may be used to
  61                 query and change the system clock and its
  62                 settings.</para>
  63         </refsect1>
  64
  65         <refsect1>
  66                 <title>Options</title>
  67
  68                 <para>The following options are understood:</para>
  69
  70                 <variablelist>
  71                         <varlistentry>
  72                                 <term><option>-h</option></term>
  73                                 <term><option>--help</option></term>
  74
  75                                 <listitem><para>Prints a short help
  76                                 text and exits.</para></listitem>
  77                         </varlistentry>
  78
  79                         <varlistentry>
  80                                 <term><option>--version</option></term>
  81
  82                                 <listitem><para>Prints a short version
  83                                 string and exits.</para></listitem>
  84                         </varlistentry>
  85
  86                         <varlistentry>
  87                                 <term><option>--no-pager</option></term>
  88
  89                                 <listitem><para>Do not pipe output into a
  90                                 pager.</para></listitem>
  91                         </varlistentry>
  92
  93                         <varlistentry>
  94                                 <term><option>--no-ask-password</option></term>
  95
  96                                 <listitem><para>Do not query the user
  97                                 for authentication for privileged
  98                                 operations.</para></listitem>
  99                         </varlistentry>
 100
 101                         <varlistentry>
 102                                 <term><option>-H</option></term>
 103                                 <term><option>--host=</option></term>
 104
 105                                 <listitem><para>Execute the operation
 106                                 remotely. Specify a hostname, or
 107                                 username and hostname separated by <literal>@</literal>,
 108                                 to connect to. This will use SSH to
 109                                 talk to the remote machine manager
 110                                 instance.</para></listitem>
 111                         </varlistentry>
 112
 113                         <varlistentry>
 114                                 <term><option>-M</option></term>
 115                                 <term><option>--machine=</option></term>
 116
 117                                 <listitem><para>Execute operation on a
 118                                 local container. Specify a container
 119                                 name to connect to.</para></listitem>
 120                         </varlistentry>
 121
 122                         <varlistentry>
 123                                 <term><option>--adjust-system-clock</option></term>
 124
 125                                 <listitem><para>If
 126                                 <command>set-local-rtc</command> is
 127                                 invoked and this option is passed, the
 128                                 system clock is synchronized from the
 129                                 RTC again, taking the new setting into
 130                                 account. Otherwise, the RTC is
 131                                 synchronized from the system
 132                                 clock.</para></listitem>
 133                         </varlistentry>
 134                 </variablelist>
 135
 136                 <para>The following commands are understood:</para>
 137
 138                 <variablelist>
 139                         <varlistentry>
 140                                 <term><command>status</command></term>
 141
 142                                 <listitem><para>Show current settings
 143                                 of the system clock and
 144                                 RTC.</para></listitem>
 145                         </varlistentry>
 146
 147                         <varlistentry>
 148                                 <term><command>set-time [TIME]</command></term>
 149
 150                                 <listitem><para>Set the system clock
 151                                 to the specified time. This will also
 152                                 update the RTC time accordingly. The time
 153                                 may be specified in the format
 154                                 "2012-10-30
 155                                 18:17:16".</para></listitem>
 156                         </varlistentry>
 157
 158                         <varlistentry>
 159                                 <term><command>set-timezone [TIMEZONE]</command></term>
 160
 161                                 <listitem><para>Set the system time
 162                                 zone to the specified value. Available
 163                                 timezones can be listed with
 164                                 <command>list-timezones</command>. If
 165                                 the RTC is configured to be in the
 166                                 local time, this will also update the
 167                                 RTC time. This call will alter the
 168                                 <filename>/etc/localtime</filename>
 169                                 symlink. See
 170                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 171                                 for more
 172                                 information.</para></listitem>
 173                         </varlistentry>
 174
 175                         <varlistentry>
 176                                 <term><command>list-timezones</command></term>
 177
 178                                 <listitem><para>List available time
 179                                 zones, one per line. Entries from the
 180                                 list can be set as the system
 181                                 timezone with
 182                                 <command>set-timezone</command>.</para></listitem>
 183                         </varlistentry>
 184
 185                         <varlistentry>
 186                                 <term><command>set-local-rtc [BOOL]</command></term>
 187
 188                                 <listitem><para>Takes a boolean
 189                                 argument. If <literal>0</literal>, the
 190                                 system is configured to maintain the
 191                                 RTC in universal time. If
 192                                 <literal>1</literal>, it will maintain
 193                                 the RTC in local time instead. Note
 194                                 that maintaining the RTC in the local
 195                                 timezone is not fully supported and
 196                                 will create various problems with time
 197                                 zone changes and daylight saving
 198                                 adjustments. If at all possible, keep the
 199                                 RTC in UTC mode. Note that invoking this
 200                                 will also synchronize the RTC from the
 201                                 system clock, unless
 202                                 <option>--adjust-system-clock</option> is
 203                                 passed (see above). This command will
 204                                 change the 3rd line of
 205                                 <filename>/etc/adjtime</filename>, as
 206                                 documented in
 207                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
 208                         </varlistentry>
 209
 210                         <varlistentry>
 211                                 <term><command>set-ntp [BOOL]</command></term>
 212
 213                                 <listitem><para>Takes a boolean
 214                                 argument. Controls whether NTP based
 215                                 network time synchronization is
 216                                 enabled (if
 217                                 available).</para></listitem>
 218                         </varlistentry>
 219
 220                 </variablelist>
 221
 222         </refsect1>
 223
 224         <refsect1>
 225                 <title>Exit status</title>
 226
 227                 <para>On success, 0 is returned, a non-zero failure
 228                 code otherwise.</para>
 229         </refsect1>
 230
 231         <xi:include href="less-variables.xml" />
 232
 233         <refsect1>
 234                 <title>Examples</title>
 235                 <para>Show current settings:
 236                 <programlisting>$ timedatectl
 237       Local time: Fri, 2012-11-02 09:26:46 CET
 238   Universal time: Fri, 2012-11-02 08:26:46 UTC
 239         RTC time: Fri, 2012-11-02 08:26:45
 240         Timezone: Europe/Warsaw
 241       UTC offset: +0100
 242      NTP enabled: no
 243 NTP synchronized: no
 244  RTC in local TZ: no
 245       DST active: no
 246  Last DST change: CEST → CET, DST became inactive
 247                   Sun, 2012-10-28 02:59:59 CEST
 248                   Sun, 2012-10-28 02:00:00 CET
 249  Next DST change: CET → CEST, DST will become active
 250                   the clock will jump one hour forward
 251                   Sun, 2013-03-31 01:59:59 CET
 252                   Sun, 2013-03-31 03:00:00 CEST</programlisting>
 253                 </para>
 254
 255                 <para>Enable an NTP daemon (chronyd):
 256                 <programlisting>$ timedatectl set-ntp true
 257 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
 258 Authentication is required to control whether network time synchronization shall be enabled.
 259 Authenticating as: user
 260 Password: ********
 261 ==== AUTHENTICATION COMPLETE ===</programlisting>
 262
 263                 <programlisting>$ systemctl status chronyd.service
 264 chronyd.service - NTP client/server
 265           Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
 266           Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
 267 ...</programlisting>
 268                 </para>
 269         </refsect1>
 270
 271         <refsect1>
 272                 <title>See Also</title>
 273                 <para>
 274                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 275                         <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 276                         <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 277                         <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 278                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 279                         <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 280                 </para>
 281         </refsect1>
 282
 283 </refentry>