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7 This file is part of systemd.
9 Copyright 2010 Lennart Poettering
11 systemd is free software; you can redistribute it and/or modify it
12 under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2 of the License, or
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25 <refentry id="systemd.timer">
27 <title>systemd.timer</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>systemd.timer</refentrytitle>
42 <manvolnum>5</manvolnum>
46 <refname>systemd.timer</refname>
47 <refpurpose>systemd timer configuration files</refpurpose>
51 <para><filename>systemd.timer</filename></para>
55 <title>Description</title>
57 <para>A unit configuration file whose name ends in
58 <filename>.timer</filename> encodes information about
59 a timer controlled and supervised by systemd, for
60 timer-based activation.</para>
62 <para>This man page lists the configuration options
63 specific to this unit type. See
64 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
65 for the common options of all unit configuration
66 files. The common configuration items are configured
67 in the generic [Unit] and [Install] sections. The
68 timer specific configuration options are configured in
69 the [Timer] section.</para>
71 <para>For each timer file, a matching unit file must
72 exist, describing the unit to activate when the timer
73 elapses. By default, a service by the same name as the
74 timer (except for the suffix) is activated. Example: a
75 timer file <filename>foo.timer</filename> activates a
76 matching service <filename>foo.service</filename>. The
77 unit to activate may be controlled by
78 <varname>Unit=</varname> (see below).</para>
82 <title>Options</title>
84 <para>Timer files must include a [Timer] section,
85 which carries information about the timer it
86 defines. The options specific to the [Timer] section
87 of timer units are the following:</para>
91 <term><varname>OnActive=</varname></term>
92 <term><varname>OnBootup=</varname></term>
93 <term><varname>OnStartup=</varname></term>
94 <term><varname>OnUnitActive=</varname></term>
95 <term><varname>OnUnitInactive=</varname></term>
97 <listitem><para>Defines timers
98 relative to different starting points:
99 <varname>OnActive=</varname> defines a
100 timer relative to the moment the timer
102 activated. <varname>OnBootup=</varname>
103 defines a timer relative to when the
105 up. <varname>OnStartup=</varname>
106 defines a timer relative to when
108 started. <varname>OnUnitActive=</varname>
109 defines a timer relative to when the
110 unit the timer is activating was last
111 activated. <varname>OnUnitInactive=</varname>
112 defines a timer relative to when the
113 unit the timer is activating was last
116 <para>Multiple directives may be
117 combined of the same and of different
118 types. For example, by combining
119 <varname>OnBoot=</varname> and
120 <varname>OnUnitActive=</varname> it is
121 possible to define a timer that
122 elapses in regular intervals and
123 activates a specific service each
126 <para>The arguments to the directives
127 are time spans configured in
128 seconds. Example: "OnBoot=50" means
129 50s after boot-up. The argument may
130 also include time units. Example:
131 "OnBoot=5h 30min" means 5 hours and 30
132 minutes after boot-up. For details
133 about the syntax of time spans see
134 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
136 <para>If a timer configured with
137 <varname>OnBootup=</varname> or
138 <varname>OnStartup=</varname> is
139 already in the past when the timer
140 unit is activated, it will immediately
141 elapse and the configured unit is
142 started. This is not the case for
143 timers defined in the other
144 directives.</para></listitem>
146 <para>These are monotonic timers,
147 independent of wall-clock time and timezones. If the
148 computer is temporarily suspended, the
149 monotonic clock stops too.</para>
153 <term><varname>Unit=</varname></term>
155 <listitem><para>The unit to activate
156 when this timer elapses. The argument is a
157 unit name, whose suffix is not
158 <filename>.timer</filename>. If not
159 specified, this value defaults to a
160 service that has the same name as the
161 timer unit, except for the
162 suffix. (See above.) It is recommended,
163 that the unit name that is activated
164 and the unit name of the timer unit
165 are named identical, except for the
166 suffix.</para></listitem>
172 <title>See Also</title>
174 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
175 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
176 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
177 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>