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 { ... };
};
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"]").
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.
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
- 2.
- the usual interface versioning guidelines
- 3.
- More information on how the system clock and RTC
interact