Picking shipping method based on Time in Transit"

I sell perishable food and all my orders must be shipped next day. Looking at UPS as the shipper, I can use "UPS Next Day Air Saver" and "UPS Ground" *IF* the orders ship to a nearby destination. Needless to say, ground is cheaper than Next Day service. UPS suggested that I use their time in transit functionality so if UPS Ground to the recipient's ZIP code is one day it will use that option and if Time in Transit for Ground is longer than one day it will use UPS Next Day Air Saver. How can I accomplish this with OC using the UPS shipping extension?

Thanks
AP

I can't say how to base the available rates on the UPS Time in Transit, but if you know the zip code areas where the rates should be offered, you could use Restrict Shipping Methods to limit which one appears, based on the customer's location. For example:

RESTRICTION #1
Shipping Methods: UPS
Rule: Shipping Rate is UPS Ground
Rule: Postcode is 12300-12399, 12500-12599

RESTRICTION #2
Shipping Methods: UPS
Rule: Shipping Rate is UPS Next Day Air Saver
Rule: Postcode is not 12300-12399, 12500-12599

Feel free to take a look at the screenshots and demo site, and if you're interested let me know at www.getclearthinking.com/contact if you have any further questions.