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

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

ORG.FREEDESKTOP.TIMEDATE1(5)g.freedesktop.timedate1.FREEDESKTOP.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 2020-09-18.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-09-18.)  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 246                                     ORG.FREEDESKTOP.TIMEDATE1(5)

Pages that refer to this page: 30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)systemd-timedated(8)systemd-timedated.service(8)