1ORG.FREEDESKTOP.TIMEDATE1(5)org.freedesktop.timedateO1RG.FREEDESKTOP.TIMEDATE1(5)
2
6 org.freedesktop.timedate1 - The D-Bus interface of systemd-timedated
7
9 systemd-timedated.service(8) is a system service that can be used to
10 control the system time and related settings. This page describes the
11 D-Bus interface.
12
14 The service exposes the following interfaces on the bus:
15 node /org/freedesktop/timedate1 {
17 interface org.freedesktop.timedate1 {
18 methods:
19 SetTime(in x usec_utc,
20 in b relative,
21 in b interactive);
22 SetTimezone(in s timezone,
23 in b interactive);
24 SetLocalRTC(in b local_rtc,
25 in b fix_system,
26 in b interactive);
27 SetNTP(in b use_ntp,
28 in b interactive);
29 ListTimezones(out as timezones);
30 properties:
31 readonly s Timezone = '...';
32 readonly b LocalRTC = ...;
33 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
34 readonly b CanNTP = ...;
35 readonly b NTP = ...;
36 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
37 readonly b NTPSynchronized = ...;
38 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
39 readonly t TimeUSec = ...;
40 @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
41 readonly t RTCTimeUSec = ...;
42 };
43 interface org.freedesktop.DBus.Peer { ... };
44 interface org.freedesktop.DBus.Introspectable { ... };
45 interface org.freedesktop.DBus.Properties { ... };
46 };
47 Methods
63 Use SetTime() to change the system clock. Pass a value of microseconds
64 since the UNIX epoch (1 Jan 1970 UTC). If relative is true, the passed
65 usec value will be added to the current system time. If it is false,
66 the current system time will be set to the passed usec value. If the
67 system time is set with this method, the RTC will be updated as well.
68 Use SetTimezone() to set the system timezone. Pass a value like
70 "Europe/Berlin" to set the timezone. Valid timezones are listed in
71 /usr/share/zoneinfo/zone.tab. If the RTC is configured to be maintained
72 in local time, it will be updated accordingly.
73 Use SetLocalRTC() to control whether the RTC is in local time or UTC.
75 It is strongly recommended to maintain the RTC in UTC. However, some
76 OSes (Windows) maintain the RTC in local time, which might make it
77 necessary to enable this feature. Note that this might create various
78 problems as daylight changes could be missed. If fix_system is "true",
79 the time from the RTC is read again and the system clock is adjusted
80 according to the new setting. If fix_system is "false", the system time
81 is written to the RTC taking the new setting into account. Use
82 fix_system=true in installers and livecds where the RTC is probably
83 more reliable than the system time. Use fix_system=false in
84 configuration UIs that are run during normal operation and where the
85 system clock is probably more reliable than the RTC.
86 Use SetNTP() to control whether the system clock is synchronized with
88 the network using systemd-timesyncd. This will enable and start or
89 disable and stop the chosen time synchronization service.
90 ListTimezones() returns a list of time zones known on the local system
92 as an array of names ("["Africa/Abidjan", "Africa/Accra", ...,
93 "UTC"]").
94 Properties
96 Timezone shows the currently configured time zone. LocalRTC shows
97 whether the RTC is configured to use UTC (false), or the local time
98 zone (true). CanNTP shows whether a service to perform time
99 synchronization over the network is available, and NTP shows whether
100 such a service is enabled.
101 NTPSynchronized shows whether the kernel reports the time as
103 synchronized (c.f. adjtimex(3)). TimeUSec and RTCTimeUSec show the
104 current time on the system and in the RTC. The purpose of those three
105 properties is to allow remote clients to access this information over
106 D-Bus. Local clients can access the information directly.
107 Whenever the Timezone and LocalRTC settings are changed via the daemon,
109 PropertyChanged signals are sent out to which clients can subscribe.
110 Note that this service will not inform you about system time changes.
112 Use timerfd(3) with CLOCK_REALTIME and TFD_TIMER_CANCEL_ON_SET for
113 that.
114 Security
116 The interactive boolean parameters can be used to control whether
117 polkit[1] should interactively ask the user for authentication
118 credentials if required.
119 The polkit action for SetTimezone() is
121 org.freedesktop.timedate1.set-timezone. For SetLocalRTC() it is
122 org.freedesktop.timedate1.set-local-rtc, for SetTime() it is
123 org.freedesktop.timedate1.set-time and for SetNTP() it is
124 org.freedesktop.timedate1.set-ntp. ListTimezones() does not require
125 any privileges.
126
128 Example 1. Introspect org.freedesktop.timedate1 on the bus
129 $ gdbus introspect --system \
131 --dest org.freedesktop.timedate1 \
132 --object-path /org/freedesktop/timedate1
133
136 These D-Bus interfaces follow the usual interface versioning
137 guidelines[2].
138
140 More information on how the system clock and RTC interact[3]
141
143 1. polkit
144 https://www.freedesktop.org/software/polkit/docs/latest/
145 2. the usual interface versioning guidelines
147 https://0pointer.de/blog/projects/versioning-dbus.html
148 3. More information on how the system clock and RTC interact
150 https://lists.freedesktop.org/archives/systemd-devel/2011-May/002526.html
151systemd 254 ORG.FREEDESKTOP.TIMEDATE1(5)