NAME
timedatectl - Control the system time and dateSYNOPSIS
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: statusShow 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-statusShow 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-passwordDo 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=[email protected]"). 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_LEVELThe 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.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER (as well
as $PAGER) will be silently ignored.
$SYSTEMD_LESS
Override the options passed to less (by
default "FRSXMK").
Users might want to change two options in particular:
K
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
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.
Override the charset passed to less (by
default "utf-8", if the invoking terminal is determined to be UTF-8
compatible).
Note that setting the regular $LESSCHARSET environment variable has no
effect for less invocations by systemd tools.
$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
$ 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 ...
$ 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 252 |