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
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