timedatectl(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | COMMANDS | OPTIONS | EXIT STATUS | ENVIRONMENT | EXAMPLES | SEE ALSO | COLOPHON

TIMEDATECTL(1)                   timedatectl                  TIMEDATECTL(1)

NAME         top

       timedatectl - Control the system time and date

SYNOPSIS         top

       timedatectl [OPTIONS...] {COMMAND}

DESCRIPTION         top

       timedatectl may be used to query and change the system clock and its
       settings, and enable or disable time synchronization services.

       Use systemd-firstboot(1) to initialize the system time zone for
       mounted (but not booted) system images.

       timedatectl may be used to show the current status of time
       synchronization services, for example systemd-timesyncd.service(8).

COMMANDS         top

       The following commands are understood:

       status
           Show current settings of the system clock and RTC, including
           whether network time synchronization is active. If no command is
           specified, this is the implied default.

       show
           Show the same information as status, but in machine readable
           form. This command is intended to be used whenever
           computer-parsable output is required. Use status if you are
           looking for formatted human-readable output.

           By default, empty properties are suppressed. Use --all to show
           those too. To select specific properties to show, use
           --property=.

       set-time [TIME]
           Set the system clock to the specified time. This will also update
           the RTC time accordingly. The time may be specified in the format
           "2012-10-30 18:17:16".

       set-timezone [TIMEZONE]
           Set the system time zone to the specified value. Available
           timezones can be listed with list-timezones. If the RTC is
           configured to be in the local time, this will also update the RTC
           time. This call will alter the /etc/localtime symlink. See
           localtime(5) for more information.

       list-timezones
           List available time zones, one per line. Entries from the list
           can be set as the system timezone with set-timezone.

       set-local-rtc [BOOL]
           Takes a boolean argument. If "0", the system is configured to
           maintain the RTC in universal time. If "1", it will maintain the
           RTC in local time instead. Note that maintaining the RTC in the
           local timezone is not fully supported and will create various
           problems with time zone changes and daylight saving adjustments.
           If at all possible, keep the RTC in UTC mode. Note that invoking
           this will also synchronize the RTC from the system clock, unless
           --adjust-system-clock is passed (see above). This command will
           change the 3rd line of /etc/adjtime, as documented in hwclock(8).

       set-ntp [BOOL]
           Takes a boolean argument. Controls whether network time
           synchronization is active and enabled (if available). If the
           argument is true, this enables and starts the first existing
           network synchronization service. If the argument is false, then
           this disables and stops the known network synchronization
           services. The way that the list of services is built is described
           below.

   systemd-timesyncd Commands
       The following commands are specific to systemd-timesyncd.service(8).

       timesync-status
           Show current status of systemd-timesyncd.service(8). If --monitor
           is specified, then this will monitor the status updates.

       show-timesync
           Show the same information as timesync-status, but in machine
           readable form. This command is intended to be used whenever
           computer-parsable output is required. Use timesync-status if you
           are looking for formatted human-readable output.

           By default, empty properties are suppressed. Use --all to show
           those too. To select specific properties to show, use
           --property=.

       ntp-servers INTERFACE SERVER...
           Set the interface specific NTP servers. This command can be used
           only when the interface is managed by systemd-networkd.

       revert INTERFACE
           Revert the interface specific NTP servers. This command can be
           used only when the interface is managed by systemd-networkd.

OPTIONS         top

       The following options are understood:

       --no-ask-password
           Do not query the user for authentication for privileged
           operations.

       --adjust-system-clock
           If set-local-rtc is invoked and this option is passed, the system
           clock is synchronized from the RTC again, taking the new setting
           into account. Otherwise, the RTC is synchronized from the system
           clock.

       --monitor
           If timesync-status is invoked and this option is passed, then
           timedatectl monitors the status of systemd-timesyncd.service(8)
           and updates the outputs. Use Ctrl+C to terminate the monitoring.

       -a, --all
           When showing properties of systemd-timesyncd.service(8), show all
           properties regardless of whether they are set or not.

       -p, --property=
           When showing properties of systemd-timesyncd.service(8), limit
           display to certain properties as specified as argument. If not
           specified, all set properties are shown. The argument should be a
           property name, such as "ServerName". If specified more than once,
           all properties with the specified names are shown.

       --value
           When printing properties with show-timesync, only print the
           value, and skip the property name and "=".

       -H, --host=
           Execute the operation remotely. Specify a hostname, or a username
           and hostname separated by "@", to connect to. The hostname may
           optionally be suffixed by a port ssh is listening on, separated
           by ":", and then a container name, separated by "/", which
           connects directly to a specific container on the specified host.
           This will use SSH to talk to the remote machine manager instance.
           Container names may be enumerated with machinectl -H HOST. Put
           IPv6 addresses in brackets.

       -M, --machine=
           Execute operation on a local container. Specify a container name
           to connect to.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

       --no-pager
           Do not pipe output into a pager.

EXIT STATUS         top

       On success, 0 is returned, a non-zero failure code otherwise.

ENVIRONMENT         top

       $SYSTEMD_PAGER
           Pager to use when --no-pager is not given; overrides $PAGER. If
           neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known
           pager implementations are tried in turn, including less(1) and
           more(1), until one is found. If no pager implementation is
           discovered no pager is invoked. Setting this environment variable
           to an empty string or the value "cat" is equivalent to passing
           --no-pager.

       $SYSTEMD_LESS
           Override the options passed to less (by default "FRSXMK").

           Users might want to change two options in particular:

           K
               This option instructs the pager to exit immediately when
               Ctrl+C is pressed. To allow less to handle Ctrl+C itself to
               switch back to the pager command prompt, unset this option.

               If the value of $SYSTEMD_LESS does not include "K", and the
               pager that is invoked is less, Ctrl+C will be ignored by the
               executable, and needs to be handled by the pager.

           X
               This option instructs the pager to not send termcap
               initialization and deinitialization strings to the terminal.
               It is set by default to allow command output to remain
               visible in the terminal even after the pager exits.
               Nevertheless, this prevents some pager functionality from
               working, in particular paged output cannot be scrolled with
               the mouse.

           See less(1) for more discussion.

       $SYSTEMD_LESSCHARSET
           Override the charset passed to less (by default "utf-8", if the
           invoking terminal is determined to be UTF-8 compatible).

       $SYSTEMD_COLORS
           The value must be a boolean. Controls whether colorized output
           should be generated. This can be specified to override the
           decision that systemd makes based on $TERM and what the console
           is connected to.

       $SYSTEMD_URLIFY
           The value must be a boolean. Controls whether clickable links
           should be generated in the output for terminal emulators
           supporting this. This can be specified to override the decision
           that systemd makes based on $TERM and other conditions.

EXAMPLES         top

       Show current settings:

           $ timedatectl
                          Local time: Thu 2017-09-21 16:08:56 CEST
                      Universal time: Thu 2017-09-21 14:08:56 UTC
                            RTC time: Thu 2017-09-21 14:08:56
                           Time zone: Europe/Warsaw (CEST, +0200)
           System clock synchronized: yes
                         NTP service: active
                     RTC in local TZ: no

       Enable network time synchronization:

           $ timedatectl set-ntp true
           ==== AUTHENTICATING FOR org.freedesktop.timedate1.set-ntp ===
           Authentication is required to control whether network time synchronization shall be enabled.
           Authenticating as: user
           Password: ********
           ==== AUTHENTICATION COMPLETE ===

           $ systemctl status systemd-timesyncd.service
           ● systemd-timesyncd.service - Network Time Synchronization
              Loaded: loaded (/usr/lib/systemd/system/systemd-timesyncd.service; enabled)
              Active: active (running) since Mo 2015-03-30 14:20:38 CEST; 5s ago
                Docs: man:systemd-timesyncd.service(8)
            Main PID: 595 (systemd-timesyn)
              Status: "Using Time Server 216.239.38.15:123 (time4.google.com)."
              CGroup: /system.slice/systemd-timesyncd.service
                      └─595 /usr/lib/systemd/systemd-timesyncd
           ...

       Show current status of systemd-timesyncd.service(8):

           $ timedatectl timesync-status
                  Server: 216.239.38.15 (time4.google.com)
           Poll interval: 1min 4s (min: 32s; max 34min 8s)
                    Leap: normal
                 Version: 4
                 Stratum: 1
               Reference: GPS
               Precision: 1us (-20)
           Root distance: 335us (max: 5s)
                  Offset: +316us
                   Delay: 349us
                  Jitter: 0
            Packet count: 1
               Frequency: -8.802ppm

SEE ALSO         top

       systemd(1), hwclock(8), date(1), localtime(5), systemctl(1),
       systemd-timedated.service(8), systemd-timesyncd.service(8),
       systemd-firstboot(1)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2020-06-09.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-06-09.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to man-pages@man7.org

systemd 245                                                   TIMEDATECTL(1)

Pages that refer to this page: systemd-firstboot(1)systemd-firstboot.service(1)localtime(5)30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)systemd.time(7)systemd-machined(8)systemd-machined.service(8)systemd-timedated(8)systemd-timedated.service(8)systemd-timesyncd(8)systemd-timesyncd.service(8)