man/timedatectl.xml

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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>--no-ask-password</option></term>
  73
  74                                 <listitem><para>Do not query the user
  75                                 for authentication for privileged
  76                                 operations.</para></listitem>
  77                         </varlistentry>
  78
  79                         <varlistentry>
  80                                 <term><option>-H</option></term>
  81                                 <term><option>--host=</option></term>
  82
  83                                 <listitem><para>Execute the operation
  84                                 remotely. Specify a hostname, or
  85                                 username and hostname separated by <literal>@</literal>,
  86                                 to connect to. This will use SSH to
  87                                 talk to the remote machine manager
  88                                 instance.</para></listitem>
  89                         </varlistentry>
  90
  91                         <varlistentry>
  92                                 <term><option>-M</option></term>
  93                                 <term><option>--machine=</option></term>
  94
  95                                 <listitem><para>Execute operation on a
  96                                 local container. Specify a container
  97                                 name to connect to.</para></listitem>
  98                         </varlistentry>
  99
 100                         <varlistentry>
 101                                 <term><option>--adjust-system-clock</option></term>
 102
 103                                 <listitem><para>If
 104                                 <command>set-local-rtc</command> is
 105                                 invoked and this option is passed, the
 106                                 system clock is synchronized from the
 107                                 RTC again, taking the new setting into
 108                                 account. Otherwise, the RTC is
 109                                 synchronized from the system
 110                                 clock.</para></listitem>
 111                         </varlistentry>
 112
 113                         <xi:include href="standard-options.xml" xpointer="help" />
 114                         <xi:include href="standard-options.xml" xpointer="version" />
 115                         <xi:include href="standard-options.xml" xpointer="no-pager" />
 116                 </variablelist>
 117
 118                 <para>The following commands are understood:</para>
 119
 120                 <variablelist>
 121                         <varlistentry>
 122                                 <term><command>status</command></term>
 123
 124                                 <listitem><para>Show current settings
 125                                 of the system clock and
 126                                 RTC.</para></listitem>
 127                         </varlistentry>
 128
 129                         <varlistentry>
 130                                 <term><command>set-time [TIME]</command></term>
 131
 132                                 <listitem><para>Set the system clock
 133                                 to the specified time. This will also
 134                                 update the RTC time accordingly. The time
 135                                 may be specified in the format
 136                                 "2012-10-30
 137                                 18:17:16".</para></listitem>
 138                         </varlistentry>
 139
 140                         <varlistentry>
 141                                 <term><command>set-timezone [TIMEZONE]</command></term>
 142
 143                                 <listitem><para>Set the system time
 144                                 zone to the specified value. Available
 145                                 timezones can be listed with
 146                                 <command>list-timezones</command>. If
 147                                 the RTC is configured to be in the
 148                                 local time, this will also update the
 149                                 RTC time. This call will alter the
 150                                 <filename>/etc/localtime</filename>
 151                                 symlink. See
 152                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 153                                 for more
 154                                 information.</para></listitem>
 155                         </varlistentry>
 156
 157                         <varlistentry>
 158                                 <term><command>list-timezones</command></term>
 159
 160                                 <listitem><para>List available time
 161                                 zones, one per line. Entries from the
 162                                 list can be set as the system
 163                                 timezone with
 164                                 <command>set-timezone</command>.</para></listitem>
 165                         </varlistentry>
 166
 167                         <varlistentry>
 168                                 <term><command>set-local-rtc [BOOL]</command></term>
 169
 170                                 <listitem><para>Takes a boolean
 171                                 argument. If <literal>0</literal>, the
 172                                 system is configured to maintain the
 173                                 RTC in universal time. If
 174                                 <literal>1</literal>, it will maintain
 175                                 the RTC in local time instead. Note
 176                                 that maintaining the RTC in the local
 177                                 timezone is not fully supported and
 178                                 will create various problems with time
 179                                 zone changes and daylight saving
 180                                 adjustments. If at all possible, keep the
 181                                 RTC in UTC mode. Note that invoking this
 182                                 will also synchronize the RTC from the
 183                                 system clock, unless
 184                                 <option>--adjust-system-clock</option> is
 185                                 passed (see above). This command will
 186                                 change the 3rd line of
 187                                 <filename>/etc/adjtime</filename>, as
 188                                 documented in
 189                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
 190                         </varlistentry>
 191
 192                         <varlistentry>
 193                                 <term><command>set-ntp [BOOL]</command></term>
 194
 195                                 <listitem><para>Takes a boolean
 196                                 argument. Controls whether NTP based
 197                                 network time synchronization is
 198                                 enabled (if
 199                                 available).</para></listitem>
 200                         </varlistentry>
 201
 202                 </variablelist>
 203
 204         </refsect1>
 205
 206         <refsect1>
 207                 <title>Exit status</title>
 208
 209                 <para>On success, 0 is returned, a non-zero failure
 210                 code otherwise.</para>
 211         </refsect1>
 212
 213         <xi:include href="less-variables.xml" />
 214
 215         <refsect1>
 216                 <title>Examples</title>
 217                 <para>Show current settings:
 218                 <programlisting>$ timedatectl
 219       Local time: Fri, 2012-11-02 09:26:46 CET
 220   Universal time: Fri, 2012-11-02 08:26:46 UTC
 221         RTC time: Fri, 2012-11-02 08:26:45
 222         Timezone: Europe/Warsaw
 223       UTC offset: +0100
 224      NTP enabled: no
 225 NTP synchronized: no
 226  RTC in local TZ: no
 227       DST active: no
 228  Last DST change: CEST → CET, DST became inactive
 229                   Sun, 2012-10-28 02:59:59 CEST
 230                   Sun, 2012-10-28 02:00:00 CET
 231  Next DST change: CET → CEST, DST will become active
 232                   the clock will jump one hour forward
 233                   Sun, 2013-03-31 01:59:59 CET
 234                   Sun, 2013-03-31 03:00:00 CEST</programlisting>
 235                 </para>
 236
 237                 <para>Enable an NTP daemon (chronyd):
 238                 <programlisting>$ timedatectl set-ntp true
 239 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
 240 Authentication is required to control whether network time synchronization shall be enabled.
 241 Authenticating as: user
 242 Password: ********
 243 ==== AUTHENTICATION COMPLETE ===</programlisting>
 244
 245                 <programlisting>$ systemctl status chronyd.service
 246 chronyd.service - NTP client/server
 247           Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
 248           Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
 249 ...</programlisting>
 250                 </para>
 251         </refsect1>
 252
 253         <refsect1>
 254                 <title>See Also</title>
 255                 <para>
 256                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 257                         <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 258                         <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 259                         <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 260                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 261                         <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 262                 </para>
 263         </refsect1>
 264
 265 </refentry>