timedatectl

TIMEDATECTL(1)                     timedatectl                    TIMEDATECTL(1)



NAME
       timedatectl - Control the system time and date

SYNOPSIS
       timedatectl [OPTIONS...] {COMMAND}

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

ENVIRONMENT
       $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_PAGERSECURE
           Takes a boolean argument. When true, the "secure" mode of the pager
           is enabled; if false, disabled. If $SYSTEMD_PAGERSECURE is not set at
           all, secure mode is enabled if the effective UID is not the same as
           the owner of the login session, see geteuid(2) and
           sd_pid_get_owner_uid(3). In secure mode, LESSSECURE=1 will be set
           when invoking the pager, and the pager shall disable commands that
           open or create new files or start new subprocesses. When
           $SYSTEMD_PAGERSECURE is not set at all, pagers which are not known to
           implement secure mode will not be used. (Currently only less(1)
           implements secure mode.)

           Note: when commands are invoked with elevated privileges, for example
           under sudo(8) or pkexec(1), care must be taken to ensure that
           unintended interactive features are not enabled. "Secure" mode for
           the pager may be enabled automatically as describe above. Setting
           SYSTEMD_PAGERSECURE=0 or not removing it from the inherited
           environment allows the user to invoke arbitrary commands. Note that
           if the $SYSTEMD_PAGER or $PAGER variables are to be honoured,
           $SYSTEMD_PAGERSECURE must be set too. It might be reasonable to
           completely disable the pager using --no-pager instead.

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



systemd 247                                                       TIMEDATECTL(1)