Below are links to some key questions regarding Absence & Substitute's Custom Reports:
Custom Report Glossary of Terms
How Do I Create a Custom Report?
How Do I Select Different Date Formats?
How Do I Select Different Hour Formats?
What is a Custom Job Report vs. a Custom Job Segment Report?
Why is Absence & Substitute Exporting Job Dates That are Outside of the Specified Date Range?
How to set a report as public or private
How to add owners to public reports
How to add owners to private reports
How to add readers to private reports