Hi
We just launched our site this week. We are a ready meals food delivery service, based in New Zealand (www.aki2you.co.nz) where Kai is Maori for food 
Our problem is how do we manage separating out the meals for delivery on two days? How do we make sure we can capture two local delivery charges when the customer makes one purchase order but wants two deliveries.
We only deliver locally to certain post codes.
Each week we have a unique menu of 9 items
We offer pick up and local delivery.
We are not using any third party delivery service.
We deliver to specific post codes in our City, we manage this in Local delivery in Shopify
Deliveries are made on Tuesdays and Fridays.
Orders for delivery on a Tuesday must be placed by midday the Friday before.
Orders for delivery on a Friday must be placed by midday the Tuesday before.
Delivery fee is a flat $6 on a minimum order of $42
We set up each product assigned to its delivery date. eg Mac and Cheese (Tues 4 April delivery) is a unique SKU to Mac and Cheese (Fri 7 April delivery).
We then grouped all the 4 April Products in one collection, all the 7 April in another.
Delivery is a flat $6 on a minimum order of $42
However in this set up customers can put both 4 April products and 7 April products in the cart.
The cart can test overall minimum order value, but not for each delivery date.
We cant increase the Local Delivery charges based on two deliveries.
I looked at solving this with Shipping locations and making each Collection/Delivery date have its own shipping charges. However that lost the ability to use post codes to limit the delivery area.
Very much appreciate your suggestions.
cheers Andrew