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NAME | SYNOPSIS | DESCRIPTION | COMMANDS | OPTIONS | EXIT STATUS | ENVIRONMENT | EXAMPLES | SEE ALSO | COLOPHON |
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TIMEDATECTL(1) timedatectl TIMEDATECTL(1)
timedatectl - Control the system time and date
timedatectl [OPTIONS...] {COMMAND}
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).
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.
Added in version 195.
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=.
Added in version 239.
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".
Added in version 195.
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.
Added in version 195.
list-timezones
List available time zones, one per line. Entries from the
list can be set as the system timezone with set-timezone.
Added in version 195.
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).
Added in version 195.
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).
Added in version 195.
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.
Added in version 239.
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=.
Added in version 239.
ntp-servers INTERFACE SERVER...
Set the interface specific NTP servers. This command can be
used only when the interface is managed by systemd-networkd.
Added in version 243.
revert INTERFACE
Revert the interface specific NTP servers. This command can
be used only when the interface is managed by
systemd-networkd.
Added in version 243.
The following options are understood:
--no-ask-password
Do not query the user for authentication for privileged
operations.
Added in version 195.
--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.
Added in version 195.
--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.
Added in version 239.
-a, --all
When showing properties of systemd-timesyncd.service(8), show
all properties regardless of whether they are set or not.
Added in version 239.
-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.
Added in version 239.
--value
When printing properties with show-timesync, only print the
value, and skip the property name and "=".
Added in version 239.
-P
Equivalent to --value --property=, i.e. shows the value of
the property without the property name or "=". Note that
using -P once will also affect all properties listed with
-p/--property=.
Added in version 256.
-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.
On success, 0 is returned, a non-zero failure code otherwise.
$SYSTEMD_LOG_LEVEL
The maximum log level of emitted messages (messages with a
higher log level, i.e. less important ones, will be
suppressed). Takes a comma-separated list of values. A value
may be 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. Each value may optionally be prefixed with one
of console, syslog, kmsg or journal followed by a colon to
set the maximum log level for that specific log target (e.g.
SYSTEMD_LOG_LEVEL=debug,console:info specifies to log at
debug level except when logging to the console which should
be at info level). Note that the global maximum log level
takes priority over any per target maximum log levels.
$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_LOG_RATELIMIT_KMSG
Whether to ratelimit kmsg or not. Takes a boolean. Defaults
to "true". If disabled, systemd will not ratelimit messages
written to kmsg.
$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
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.
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
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.
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
systemd(1), hwclock(8), date(1), localtime(5), systemctl(1),
systemd-timedated.service(8), systemd-timesyncd.service(8),
systemd-firstboot(1)
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 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) 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 257~devel TIMEDATECTL(1)
Pages that refer to this page: systemd-firstboot(1), localtime(5), systemd.directives(7), systemd.index(7), systemd.time(7), systemd-machined.service(8), systemd-timedated.service(8), systemd-timesyncd.service(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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