Shopify modifications & Shipstation API

We need the following: 1. Some modifications to our date picker calendar: Here is our CURRENT calendar: [login to view URL] We need the following changes completed: Visual changes: we’d like the calendar to be bigger than it is, and the design changed to look like the concept we have attached. We need different days highlighted as specified (see attached) We also need these changes made: I. If it is currently Friday, they cannot select Monday or Tuesday delivery II. Additional 9.99 charge for Mondays (only selectable Monday-Thursday) 2. Shopify back end modification: When a customer selects a delivery date, Shopify needs to automatically generate data for another field, showing a date two business days prior to the date selected. This field will be called: “Ship Date” 3. Shipstation API: We need the two fields, Delivery date and ship date, to be synced between our Shopify and our Shipstation account custom fields.