NAME

       systemd.timer - Timer unit configuration

SYNOPSIS

       timer.timer

DESCRIPTION

       A unit configuration file whose name ends in .timer encodes information about a timer controlled and
       supervised by systemd, for timer-based activation.

       This man page lists the configuration options specific to this unit type. See systemd.unit(5) for the
       common options of all unit configuration files. The common configuration items are configured in the
       generic [Unit] and [Install] sections. The timer specific configuration options are configured in the
       [Timer] section.

       For each timer file, a matching unit file must exist, describing the unit to activate when the timer
       elapses. By default, a service by the same name as the timer (except for the suffix) is activated.
       Example: a timer file foo.timer activates a matching service foo.service. The unit to activate may be
       controlled by Unit= (see below).

       Unless DefaultDependencies= is set to false, timer units will implicitly have dependencies of type
       Conflicts= and Before= on shutdown.target. These ensure that timer units are stopped cleanly prior to
       system shutdown. Only timer units involved with early boot or late system shutdown should disable this
       option.

OPTIONS

       Timer files must include a [Timer] section, which carries information about the timer it defines. The
       options specific to the [Timer] section of timer units are the following:

       OnActiveSec=, OnBootSec=, OnStartupSec=, OnUnitActiveSec=, OnUnitInactiveSec=
           Defines monotonic timers relative to different starting points: OnActiveSec= defines a timer relative
           to the moment the timer itself is activated.  OnBootSec= defines a timer relative to when the machine
           was booted up.  OnStartupSec= defines a timer relative to when systemd was first started.
           OnUnitActiveSec= defines a timer relative to when the unit the timer is activating was last
           activated.  OnUnitInactiveSec= defines a timer relative to when the unit the timer is activating was
           last deactivated.

           Multiple directives may be combined of the same and of different types. For example, by combining
           OnBootSec= and OnUnitActiveSec= it is possible to define a timer that elapses in regular intervals
           and activates a specific service each time.

           The arguments to the directives are time spans configured in seconds. Example: "OnBootSec=50" means
           50s after boot-up. The argument may also include time units. Example: "OnBootSec=5h 30min" means 5
           hours and 30 minutes after boot-up. For details about the syntax of time spans see systemd.unit(5).

           If a timer configured with OnBootSec= or OnStartupSec= is already in the past when the timer unit is
           activated, it will immediately elapse and the configured unit is started. This is not the case for
           timers defined in the other directives.

           These are monotonic timers, independent of wall-clock time and timezones. If the computer is
           temporarily suspended, the monotonic clock stops too.

           If the empty string is assigned to any of these options the list of timers is reset, and all prior
           assignments will have no effect.

       OnCalendar=
           Defines realtime (i.e. wallclock) timers via calendar event expressions. See systemd.time(7) for more
           information on the syntax of calendar event expressions. Otherwise the semantics are similar to
           OnActiveSec= and related settings.

       Unit=
           The unit to activate when this timer elapses. The argument is a unit name, whose suffix is not
           .timer. If not specified, this value defaults to a service that has the same name as the timer unit,
           except for the suffix. (See above.) It is recommended that the unit name that is activated and the
           unit name of the timer unit are named identically, except for the suffix.

SEE ALSO

       systemd(1), systemctl(8), systemd.unit(5), systemd.service(5), systemd.time(7), systemd.directives(7)

systemd 204                                                                                     SYSTEMD.TIMER(5)