Creating a recurring event (date_field) based on another date field

I'm trying to create a Drupal site where users can register to drop something off using the Date field, and then schedule a pickup date in a specified time frame after that original date (they drop something off on Monday for example, and they can pick from a drop down to pick up on Tuesday, Wednesday or Thursday).

This would all then be recurring on a weekly, semi-weekly or Monthly basis.

Is there a way to base a default date on another date field? Right now, I'm planning on creating the intial drop off date as a weekly event, and then create the 3 dates as options and use a Flag for 1-3 days to only show the appropriate pickup date when the administrator or the user pulls up the calender.