systemd Developer Lennart Poettering lennart@poettering.net 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. The following options are understood: -h --help Prints a short help text and exits. --version Prints a short version string and exits. --no-pager Do not pipe output into a pager. --no-ask-password Do not query the user for authentication for privileged operations. -P --privileged Acquire privileges via PolicyKit before executing the operation. -H --host Execute the operation remotely. Specify a hostname, or username and hostname separated by @, to connect to. This will use SSH to talk to a remote system. --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. 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 localtime5 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 hwclock8. set-ntp [BOOL] Takes a boolean argument. Controls whether NTP based network time synchronization is enabled (if available). On success 0 is returned, a non-zero failure code otherwise. $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. Show current settings: $ timedatectl Local time: Fri, 2012-11-02 09:26:46 CET Universal time: Fri, 2012-11-02 08:26:46 UTC RTC time: Fri, 2012-11-02 08:26:45 Timezone: Europe/Warsaw UTC offset: +0100 NTP enabled: no NTP synchronized: no RTC in local TZ: no DST active: no Last DST change: CEST → CET, DST became inactive Sun, 2012-10-28 02:59:59 CEST Sun, 2012-10-28 02:00:00 CET Next DST change: CET → CEST, DST will become active the clock will jump one hour forward Sun, 2013-03-31 01:59:59 CET Sun, 2013-03-31 03:00:00 CEST Enable an NTP daemon (chronyd): $ 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 chronyd.service chronyd.service - NTP client/server Loaded: loaded (/usr/lib/systemd/system/chronyd.service; enabled) Active: active (running) since Fri, 2012-11-02 09:36:25 CET; 5s ago ... systemd1, hwclock8, date1, localtime5, systemctl1, systemd-timedated.service8