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NAME | INTRODUCTION | THE D-BUS API | EXAMPLES | VERSIONING | SEE ALSO | NOTES | COLOPHON |
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ORG.FRE...TIMEDATE1(5) org.freedesktop.timedate1 ORG.FRE...TIMEDATE1(5)
org.freedesktop.timedate1 - The D-Bus interface of
systemd-timedated
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 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.
Example 1. Introspect org.freedesktop.timedate1 on the bus
$ gdbus introspect --system \
--dest org.freedesktop.timedate1 \
--object-path /org/freedesktop/timedate1
These D-Bus interfaces follow the usual interface versioning
guidelines[2].
More information on how the system clock and RTC interact[3]
1. polkit
https://www.freedesktop.org/software/polkit/docs/latest/
2. the usual interface versioning guidelines
https://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
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 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) 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
[email protected]
systemd 257~devel ORG.FRE...TIMEDATE1(5)
Pages that refer to this page: systemd.directives(7), systemd.index(7), systemd-timedated.service(8)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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