man 5 ORG.FREEDESKTOP.TIMEDATE1

ORG.FREEDESKTOP.TIMEDATE1(5org.freedesktop.timedatORG.FREEDESKTOP.TIMEDATE1(5)

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

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

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

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

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

NOTES
        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

systemd 252                                       ORG.FREEDESKTOP.TIMEDATE1(5)