timedatectl Man page

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.

Use systemd-firstboot(1) to initialize the system time zone for mounted
(but not booted) system images.

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.

-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 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.

-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.

The following commands are understood:

status
Show current settings of the system clock and RTC, including
whether network time synchronization is on. Note that whether
network time synchronization is on simply reflects whether the
systemd-timesyncd.service unit is enabled. Even if this command
shows the status as off, a different service might still
synchronize the clock with the network.

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). This enables
and starts, or disables and stops the systemd-timesyncd.service
unit. It does not affect the state of any other, unrelated network
time synchronization services that might be installed on the
system. This command is hence mostly equivalent to: systemctl
enable –now systemd-timesyncd.service and systemctl disable –now
systemd-timesyncd.service, but is protected by a different access
policy.

Note that even if time synchronization is turned off with this
command, another unrelated system service might still synchronize
the clock with the network. Also note that, strictly speaking,
systemd-timesyncd.service does more than just network time
synchronization, as it ensures a monotonic clock on systems without
RTC even if no network is available. See systemd-
timesyncd.service(8) for details about this.

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.
Setting this to an empty string or the value “cat” is equivalent to
passing –no-pager.

$SYSTEMD_LESS
Override the default options passed to less (“FRSXMK”).

EXAMPLES
Show current settings:

$ timedatectl
Local time: Di 2015-04-07 16:26:56 CEST
Universal time: Di 2015-04-07 14:26:56 UTC
RTC time: Di 2015-04-07 14:26:56
Time zone: Europe/Berlin (CEST, +0200)
Network time on: yes
NTP synchronized: yes
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

SEE ALSO

systemd, hwclock(8), date, localtime(5), systemctl, systemd-
timedated.service(8), systemd-timesyncd.service(8), systemd-
firstboot(1)

systemd 229 TIMEDATECTL(1)