Like any large scale enterprise data service, not every data process happens in the clients or on the web. There are a number of tasks that are specialized and must be scheduled to run at daily, weekly or monthly intervals. These processes run via CRON under Linux. These include scheduled fine generation, catalog ingestion support, re-shelving support among others. For Linux, an example crontab is included in the Evergreen code base at Open-ILS/examples/crontab.example:

http://git.evergreen-ils.org/?p=Evergreen.git;a=blob;f=Open-ILS/examples/crontab.example;hb=HEAD

NOTE: The following should be added to the example crontab file:

# Sitemap Generator - added in 2.7
# 12 2 * * * cd /openils/var/web && $EG_BIN_DIR/sitemap_generator --lib-hostname http://catalog.example.org

There are many useful sites on the internet that extend what man teaches you about using CRON if you need it. Just search on "crontab examples" for a current list.