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

Added in version 195.

show

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

Added in version 239.

set-time [TIME]

Added in version 195.

set-timezone [TIMEZONE]

Added in version 195.

list-timezones

Added in version 195.

set-local-rtc [BOOL]

Added in version 195.

set-ntp [BOOL]

Added in version 195.

systemd-timesyncd Commands#

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

timesync-status

Added in version 239.

show-timesync

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

Added in version 239.

ntp-serversINTERFACESERVER...

Added in version 243.

revertINTERFACE

Added in version 243.

OPTIONS#

The following options are understood:

--adjust-system-clock

Added in version 195.

--monitor

Added in version 239.

-a, --all

Added in version 239.

-p, --property=

Added in version 239.

--value

Added in version 239.

-P

Added in version 256.

-H, --host=

-M, --machine=

--no-ask-password

-h, --help

--version

--no-pager

EXIT STATUS#

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

ENVIRONMENT#

$SYSTEMD_LOG_LEVEL

$SYSTEMD_LOG_COLOR

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

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

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

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

$SYSTEMD_LOG_RATELIMIT_KMSG

$SYSTEMD_PAGER, $PAGER

Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER and $PAGER can only be used to disable the pager (with "cat" or ""), and are otherwise ignored.

$SYSTEMD_LESS

Users might want to change two options in particular:

K

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

Note that setting the regular $LESS environment variable has no effect for less invocations by systemd tools.

See less(1) for more discussion.

$SYSTEMD_LESSCHARSET

Note that setting the regular $LESSCHARSET environment variable has no effect for less invocations by systemd tools.

$SYSTEMD_PAGERSECURE

This option takes a boolean argument. When set to true, the "secure mode" of the pager is enabled. In "secure mode", LESSSECURE=1 will be set when invoking the pager, which instructs the pager to disable commands that open or create new files or start new subprocesses. Currently only less(1) is known to understand this variable and implement "secure mode".

When set to false, no limitation is placed on the pager. Setting SYSTEMD_PAGERSECURE=0 or not removing it from the inherited environment may allow the user to invoke arbitrary commands.

When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to automatically figure out if "secure mode" should be enabled and whether the pager supports it. "Secure mode" is enabled if the effective UID is not the same as the owner of the login session, see geteuid(2) and sd_pid_get_owner_uid(3), or when running under sudo(8) or similar tools ($SUDO_UID is set [1]). In those cases, SYSTEMD_PAGERSECURE=1 will be set and pagers which are not known to implement "secure mode" will not be used at all. Note that this autodetection only covers the most common mechanisms to elevate privileges and is intended as convenience. It is recommended to explicitly set $SYSTEMD_PAGERSECURE or disable the pager.

Note that if the $SYSTEMD_PAGER or $PAGER variables are to be honoured, other than to disable the pager, $SYSTEMD_PAGERSECURE must be set too.

$SYSTEMD_COLORS

$SYSTEMD_URLIFY

EXAMPLES#

Show current settings:

$ timedatectl
\n
               Local time: Thu 2017-09-21 16:08:56 CEST
\n
           Universal time: Thu 2017-09-21 14:08:56 UTC
\n
                 RTC time: Thu 2017-09-21 14:08:56
\n
                Time zone: Europe/Warsaw (CEST, +0200)
System clock synchronized: yes
\n
              NTP service: active
\n
          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
\n
   Loaded: loaded (/usr/lib/systemd/system/systemd-timesyncd.service; enabled)
\n
   Active: active (running) since Mo 2015-03-30 14:20:38 CEST; 5s ago
\n
     Docs: man:systemd-timesyncd.service(8)
\n
 Main PID: 595 (systemd-timesyn)
\n
   Status: "Using Time Server 216.239.38.15:123 (time4.google.com)."
\n
   CGroup: /system.slice/systemd-timesyncd.service
\n
           └─595 /usr/lib/systemd/systemd-timesyncd
...

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

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

NOTES#

1.

It is recommended for other tools to set and check $SUDO_UID as appropriate, treating it is a common interface.