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_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 (/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 245 TIMEDATECTL(1)

timedatectl

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