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
  26         <refentryinfo>
  27                 <title>timedatectl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>timedatectl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>timedatectl</refname>
  47                 <refpurpose>Control the system time and date</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>timedatectl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command>
  53                 </cmdsynopsis>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>timedatectl</command> may be used to
  60                 query and change the system clock and its
  61                 settings.</para>
  62         </refsect1>
  63
  64         <refsect1>
  65                 <title>Options</title>
  66
  67                 <para>The following options are understood:</para>
  68
  69                 <variablelist>
  70                         <varlistentry>
  71                                 <term><option>-h</option></term>
  72                                 <term><option>--help</option></term>
  73
  74                                 <listitem><para>Prints a short help
  75                                 text and exits.</para></listitem>
  76                         </varlistentry>
  77
  78                         <varlistentry>
  79                                 <term><option>--version</option></term>
  80
  81                                 <listitem><para>Prints a short version
  82                                 string and exits.</para></listitem>
  83                         </varlistentry>
  84
  85                         <varlistentry>
  86                                 <term><option>--no-pager</option></term>
  87
  88                                 <listitem><para>Do not pipe output into a
  89                                 pager.</para></listitem>
  90                         </varlistentry>
  91
  92                         <varlistentry>
  93                                 <term><option>--no-ask-password</option></term>
  94
  95                                 <listitem><para>Don't query the user
  96                                 for authentication for privileged
  97                                 operations.</para></listitem>
  98                         </varlistentry>
  99
 100                         <varlistentry>
 101                                 <term><option>-P</option></term>
 102                                 <term><option>--privileged</option></term>
 103
 104                                 <listitem><para>Acquire privileges via PolicyKit
 105                                 before executing the operation.</para></listitem>
 106                         </varlistentry>
 107
 108                         <varlistentry>
 109                                 <term><option>-H</option></term>
 110                                 <term><option>--host</option></term>
 111
 112                                 <listitem><para>Execute the operation
 113                                 remotely. Specify a hostname, or
 114                                 username and hostname separated by @,
 115                                 to connect to. This will use SSH to
 116                                 talk to a remote
 117                                 system.</para></listitem>
 118                         </varlistentry>
 119
 120                         <varlistentry>
 121                                 <term><option>--adjust-system-clock</option></term>
 122
 123                                 <listitem><para>If
 124                                 <command>set-local-rtc</command> is
 125                                 invoked and this option is passed the
 126                                 system clock is synchronized from the
 127                                 RTC again, taking the new setting into
 128                                 account. Otherwise the RTC is
 129                                 synchronized from the system
 130                                 clock.</para></listitem>
 131                         </varlistentry>
 132                 </variablelist>
 133
 134                 <para>The following commands are understood:</para>
 135
 136                 <variablelist>
 137                         <varlistentry>
 138                                 <term><command>status</command></term>
 139
 140                                 <listitem><para>Show current settings
 141                                 of the system clock and
 142                                 RTC.</para></listitem>
 143                         </varlistentry>
 144
 145                         <varlistentry>
 146                                 <term><command>set-time [TIME]</command></term>
 147
 148                                 <listitem><para>Set the system clock
 149                                 to the specified time. This will also
 150                                 update the RTC time accordingly. The time
 151                                 may be specified in the format
 152                                 "2012-10-30
 153                                 18:17:16".</para></listitem>
 154                         </varlistentry>
 155
 156                         <varlistentry>
 157                                 <term><command>set-timezone [TIMEZONE]</command></term>
 158
 159                                 <listitem><para>Set the system time
 160                                 zone to the specified value. Available
 161                                 timezones can be listed with
 162                                 <command>list-timezones</command>. If
 163                                 the RTC is configured to be in the
 164                                 local time this will also update the
 165                                 RTC time. This call will alter the
 166                                 <filename>/etc/localtime</filename>
 167                                 symlink. See
 168                                 <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 169                                 for more
 170                                 information.</para></listitem>
 171                         </varlistentry>
 172
 173                         <varlistentry>
 174                                 <term><command>list-timezones</command></term>
 175
 176                                 <listitem><para>List available time
 177                                 zones, one per line. Entries from the
 178                                 list can be set as the system
 179                                 timezone with
 180                                 <command>set-timezone</command>.</para></listitem>
 181                         </varlistentry>
 182
 183                         <varlistentry>
 184                                 <term><command>set-local-rtc [BOOL]</command></term>
 185
 186                                 <listitem><para>Takes a boolean
 187                                 argument. If <literal>0</literal> the
 188                                 system is configured to maintain the
 189                                 RTC in universal time, if
 190                                 <literal>1</literal> it will maintain
 191                                 the RTC in local time instead. Note
 192                                 that maintaining the RTC in the local
 193                                 timezone is not fully supported and
 194                                 will create various problems with time
 195                                 zone changes and daylight saving
 196                                 adjustments. If at all possible use
 197                                 RTC in UTC. Note that invoking this
 198                                 will also synchronize the RTC from the
 199                                 system clock, unless
 200                                 <option>--adjust-system-clock</option> is
 201                                 passed (see above). This command will
 202                                 change the 3rd line of
 203                                 <filename>/etc/adjtime</filename>, as
 204                                 documented in
 205                                 <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>
 206                         </varlistentry>
 207
 208                         <varlistentry>
 209                                 <term><command>set-ntp [BOOL]</command></term>
 210
 211                                 <listitem><para>Takes a boolean
 212                                 argument. Controls whether NTP based
 213                                 network time synchronization is
 214                                 enabled (if
 215                                 available).</para></listitem>
 216                         </varlistentry>
 217
 218                 </variablelist>
 219
 220         </refsect1>
 221
 222         <refsect1>
 223                 <title>Exit status</title>
 224
 225                 <para>On success 0 is returned, a non-zero failure
 226                 code otherwise.</para>
 227         </refsect1>
 228
 229         <refsect1>
 230                 <title>Environment</title>
 231
 232                 <variablelist class='environment-variables'>
 233                         <varlistentry>
 234                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 235                                 <listitem><para>Pager to use when
 236                                 <option>--no-pager</option> is not given;
 237                                 overrides <varname>$PAGER</varname>.  Setting
 238                                 this to an empty string or the value
 239                                 <literal>cat</literal> is equivalent to passing
 240                                 <option>--no-pager</option>.</para></listitem>
 241                         </varlistentry>
 242                 </variablelist>
 243         </refsect1>
 244
 245         <refsect1>
 246                 <title>Examples</title>
 247                 <para>Show current settings:
 248                 <programlisting>
 249 $ timedatectl
 250       Local time: Fri, 2012-11-02 09:26:46 CET
 251   Universal time: Fri, 2012-11-02 08:26:46 UTC
 252         RTC time: Fri, 2012-11-02 08:26:45
 253         Timezone: Europe/Warsaw
 254       UTC offset: +0100
 255      NTP enabled: no
 256 NTP synchronized: no
 257  RTC in local TZ: no
 258       DST active: no
 259  Last DST change: CEST → CET, DST became inactive
 260                   Sun, 2012-10-28 02:59:59 CEST
 261                   Sun, 2012-10-28 02:00:00 CET
 262  Next DST change: CET → CEST, DST will become active
 263                   the clock will jump one hour forward
 264                   Sun, 2013-03-31 01:59:59 CET
 265                   Sun, 2013-03-31 03:00:00 CEST
 266                 </programlisting>
 267                 </para>
 268
 269                 <para>Enable an NTP daemon (chronyd):
 270                 <programlisting>
 271 $ timedatectl set-ntp true
 272 ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
 273 Authentication is required to control whether network time synchronization shall be enabled.
 274 Authenticating as: user
 275 Password: ********
 276 ==== AUTHENTICATION COMPLETE ===
 277                 </programlisting>
 278
 279                 <programlisting>
 280 $ systemctl status chronyd.service
 281 chronyd.service - NTP client/server
 282           Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled)
 283           Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago
 284 ...
 285                 </programlisting>
 286                 </para>
 287         </refsect1>
 288
 289         <refsect1>
 290                 <title>See Also</title>
 291                 <para>
 292                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 293                         <citerefentry><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 294                         <citerefentry><refentrytitle>date</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 295                         <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 296                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 297                         <citerefentry><refentrytitle>systemd-timedated.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 298                 </para>
 299         </refsect1>
 300
 301 </refentry>