= Cron Task Scheduler Integration =

The periods defined by recurring events are not all recorded in a user's
free/busy collection if such events recur indefinitely. Instead, only the
periods within a certain window of time are recorded for such events. As a
consequence, free/busy collections need to be progressively expanded over
time to include periods that were ignored when previously recording
free/busy information for an event.

The `conf/cron/cron.daily/imip-agent` file contains commands that update
free/busy collections for all known users, and this should be copied to the
appropriate destination. For example:

{{{
cp conf/cron/cron.daily/imip-agent /etc/cron.daily/
}}}

Where frequency-specific directories are not supported by cron on a system, a
`crontab` entry of the appropriate format is required instead.

See the [[../EventRecurrences|guide to event recurrences]] for more information
on how recurring events are supported.

Responsibility for generating free/busy expansions lies with the
`tools/make_freebusy.py` program, which is a general tool that can also
reset the free/busy records defined for a user or those made available to a
user.
