org.freedesktop.timedate1(5) — Linux manual page

NAME | INTRODUCTION | THE D-BUS API | EXAMPLES | VERSIONING | SEE ALSO | NOTES | COLOPHON

ORG.FREEDESKTOP.TIMEDATE1(5)freedesktop.timedate1REEDESKTOP.TIMEDATE1(5)

NAME         top

       org.freedesktop.timedate1 - The D-Bus interface of
       systemd-timedated

INTRODUCTION         top

       systemd-timedated.service(8) is a system service that can be used
       to control the system time and related settings. This page
       describes the D-Bus interface.

THE D-BUS API         top

       The service exposes the following interfaces on the bus:

           node /org/freedesktop/timedate1 {
             interface org.freedesktop.timedate1 {
               methods:
                 SetTime(in  x usec_utc,
                         in  b relative,
                         in  b interactive);
                 SetTimezone(in  s timezone,
                             in  b interactive);
                 SetLocalRTC(in  b local_rtc,
                             in  b fix_system,
                             in  b interactive);
                 SetNTP(in  b use_ntp,
                        in  b interactive);
                 ListTimezones(out as timezones);
               properties:
                 readonly s Timezone = '...';
                 readonly b LocalRTC = ...;
                 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
                 readonly b CanNTP = ...;
                 readonly b NTP = ...;
                 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
                 readonly b NTPSynchronized = ...;
                 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
                 readonly t TimeUSec = ...;
                 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
                 readonly t RTCTimeUSec = ...;
             };
             interface org.freedesktop.DBus.Peer { ... };
             interface org.freedesktop.DBus.Introspectable { ... };
             interface org.freedesktop.DBus.Properties { ... };
           };

   Methods
       Use SetTime() to change the system clock. Pass a value of
       microseconds since the UNIX epoch (1 Jan 1970 UTC). If relative
       is true, the passed usec value will be added to the current
       system time. If it is false, the current system time will be set
       to the passed usec value. If the system time is set with this
       method, the RTC will be updated as well.

       Use SetTimezone() to set the system timezone. Pass a value like
       "Europe/Berlin" to set the timezone. Valid timezones are listed
       in /usr/share/zoneinfo/zone.tab. If the RTC is configured to be
       maintained in local time, it will be updated accordingly.

       Use SetLocalRTC() to control whether the RTC is in local time or
       UTC. It is strongly recommended to maintain the RTC in UTC.
       However, some OSes (Windows) maintain the RTC in local time,
       which might make it necessary to enable this feature. Note that
       this might create various problems as daylight changes could be
       missed. If fix_system is "true", the time from the RTC is read
       again and the system clock is adjusted according to the new
       setting. If fix_system is "false", the system time is written to
       the RTC taking the new setting into account. Use fix_system=true
       in installers and livecds where the RTC is probably more reliable
       than the system time. Use fix_system=false in configuration UIs
       that are run during normal operation and where the system clock
       is probably more reliable than the RTC.

       Use SetNTP() to control whether the system clock is synchronized
       with the network using systemd-timesyncd. This will enable and
       start or disable and stop the chosen time synchronization
       service.

       ListTimezones() returns a list of time zones known on the local
       system as an array of names ("["Africa/Abidjan", "Africa/Accra",
       ..., "UTC"]").

   Properties
       Timezone shows the currently configured time zone.  LocalRTC
       shows whether the RTC is configured to use UTC (false), or the
       local time zone (true).  CanNTP shows whether a service to
       perform time synchronization over the network is available, and
       NTP shows whether such a service is enabled.

       NTPSynchronized shows whether the kernel reports the time as
       synchronized (c.f.  adjtimex(3)).  TimeUSec and RTCTimeUSec show
       the current time on the system and in the RTC. The purpose of
       those three properties is to allow remote clients to access this
       information over D-Bus. Local clients can access the information
       directly.

       Whenever the Timezone and LocalRTC settings are changed via the
       daemon, PropertyChanged signals are sent out to which clients can
       subscribe.

       Note that this service will not inform you about system time
       changes. Use timerfd(3) with CLOCK_REALTIME and
       TFD_TIMER_CANCEL_ON_SET for that.

   Security
       The interactive boolean parameters can be used to control whether
       polkit[1] should interactively ask the user for authentication
       credentials if required.

       The polkit action for SetTimezone() is
       org.freedesktop.timedate1.set-timezone. For SetLocalRTC() it is
       org.freedesktop.timedate1.set-local-rtc, for SetTime() it is
       org.freedesktop.timedate1.set-time and for SetNTP() it is
       org.freedesktop.timedate1.set-ntp.  ListTimezones() does not
       require any privileges.

EXAMPLES         top

       Example 1. Introspect org.freedesktop.timedate1 on the bus

           $ gdbus introspect --system \
             --dest org.freedesktop.timedate1 \
             --object-path /org/freedesktop/timedate1

VERSIONING         top

       These D-Bus interfaces follow the usual interface versioning
       guidelines[2].

SEE ALSO         top

       More information on how the system clock and RTC interact[3]

NOTES         top

        1. polkit
           https://www.freedesktop.org/software/polkit/docs/latest/

        2. the usual interface versioning guidelines
           http://0pointer.de/blog/projects/versioning-dbus.html

        3. More information on how the system clock and RTC interact
           https://lists.freedesktop.org/archives/systemd-devel/2011-May/002526.html

COLOPHON         top

       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 2021-08-27.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2021-08-27.)  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 249                                 ORG.FREEDESKTOP.TIMEDATE1(5)

Pages that refer to this page: systemd-timedated.service(8)