Rotations are part of SARJ where all the magic happens, as this is where you can configure all the rules tailored to suit your needs!
You can configure the time of the day, the date range, the participants (or teams) of the rotation, or even particular field(s) of an issue (such as priority, components, etc.) for which the auto-assignment rules apply.
Based on your understanding of Jira, SARJ allows two configuration options for Rotations. Click on the links below to read more about them.