How to restrict learners from withdrawing an offering when start date is less or equal to 10 days?

How to restrict learners from withdrawing from an offering when the start date is less or equal to ten days?

The client needs to define a number of days within which the approval process is required: for example, in the 10 days before the Offering Start Date the approval process must occur, while 11 days before NO.

Based on the product management's response, this is possible, however I am not sure what attribute to select.

For reference: https://community.oracle.com/customerconnect/discussion/comment/866468

Thank you in advance,

Lorenzo