This web based database demonstrates the implementation of recurring tasks via workflow rules.
Create new task. Set the End Date few days after the Start Date and the Interval in days. New task instances will eventually appear (after 3-4 minutes), with Start Date shifted by the Interval, until Start Date reaches End Date.
Interested? Visit Setup | Rules | Workflow Rules to see how it works.
By the way, the same principle can be used to replicate a record number of times.
Any support materials, such as spreadsheets and real-life work samples would be very helpful as they would help us better understand your business process.