phpman > man > timedatectl(1)

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 in systemd-timedated.service(8).

   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,
           optionally prefixed by a user name to connect as and a separating "@" character. If the
           special string ".host" is used in place of the container name, a connection to the local
           system is made (which is useful to connect to a specific user's user bus: "--user
           --machine=lennart@.host"). If the "@" syntax is not used, the connection is made as root
           user. If the "@" syntax is used either the left hand side or the right hand side may be
           omitted (but not both) in which case the local user name and ".host" are implied.

       -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_LOG_LEVEL
           The maximum log level of emitted messages (messages with a higher log level, i.e. less
           important ones, will be suppressed). Either one of (in order of decreasing importance)
           emerg, alert, crit, err, warning, notice, info, debug, or an integer in the range 0...7.
           See syslog(3) for more information.

       $SYSTEMD_LOG_COLOR
           A boolean. If true, messages written to the tty will be colored according to priority.

           This setting is only useful when messages are written directly to the terminal, because
           journalctl(1) and other tools that display logs will color messages based on the log
           level on their own.

       $SYSTEMD_LOG_TIME
           A boolean. If true, console log messages will be prefixed with a timestamp.

           This setting is only useful when messages are written directly to the terminal or a file,
           because journalctl(1) and other tools that display logs will attach timestamps based on
           the entry metadata on their own.

       $SYSTEMD_LOG_LOCATION
           A boolean. If true, messages will be prefixed with a filename and line number in the
           source code where the message originates.

           Note that the log location is often attached as metadata to journal entries anyway.
           Including it directly in the message text can nevertheless be convenient when debugging
           programs.

       $SYSTEMD_LOG_TID
           A boolean. If true, messages will be prefixed with the current numerical thread ID (TID).

           Note that the this information is attached as metadata to journal entries anyway.
           Including it directly in the message text can nevertheless be convenient when debugging
           programs.

       $SYSTEMD_LOG_TARGET
           The destination for log messages. One of console (log to the attached tty),
           console-prefixed (log to the attached tty but with prefixes encoding the log level and
           "facility", see syslog(3), kmsg (log to the kernel circular log buffer), journal (log to
           the journal), journal-or-kmsg (log to the journal if available, and to kmsg otherwise),
           auto (determine the appropriate log target automatically, the default), null (disable log
           output).

       $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
           Takes a boolean argument. When true, systemd and related utilities will use colors in
           their output, otherwise the output will be monochrome. Additionally, the variable can
           take one of the following special values: "16", "256" to restrict the use of colors to
           the base 16 or 256 ANSI colors, respectively. This can be specified to override the
           automatic decision 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 (/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 /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 249                                                                           TIMEDATECTL(1)