Goto an ical provider, such as google.( https://www.google.com/calendar/ ) Create a PUBLIC, ical calendar, with various repeated events, with different rules and conditions. Make sure you name the events, meaningfully to later identify their recurrence pattern from their name. Get the ical export url (under settings for google) Go to your moodle>calendar>subscriptions> import the ical Make sure events are created in the calendar as expected. (please note MDL-44124 is a known issue) Run unit tests in calendar/tests/rrule_manager_tests.php and make sure they pass.