Adds a Saturday Delivery checkbox to FedEx delivery methods for eligible FedEx services. When enabled, orders placed on qualifying Thursday or Friday shipping days can use Saturday delivery pricing, while other days continue to use normal delivery behavior without errors.

Task: https://www.odoo.com/web?#id=24185&view_type=form&model=project.task&action=333&active_id=131&menu_id=4720
Pad: https://pad.odoo.com/p/r.d00e2b1d45c89c9bd8d3fe6bbc674126