timedatectl

systemd
Developer Lennart Poettering lennart@poettering.net
timedatectl 1
timedatectl Control the system time and date
`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.

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.

## 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 (/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
    …

## See Also

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