We use UPS to ship our 2nd day and overnight packages. UPS as a company uses only Monday-Friday (not including holidays) for business day movement calculations. However, Amazon includes Saturday as a business day for it's shipping calculations. This makes it impossible for us to deliver to customers in a timely manner and keep pricing guidance correct.

AMAZON - THIS IS AN ISSUE THAT MANY SELLERS HAVE SPOKEN ABOUT ON THE SELLER FORUMS and yet there is no resolution from you on this. Please express to the team(s) that works on shipping calculations that Saturday should not be included in the shipping calculations for 3rd party sellers. Therefore, an overnight package purchased on Friday will be delivered on Monday. A second-day package purchased on Thursday will be delivered on Monday. In neither case should Saturday delivery be possible since that is either an extra charge OR not possible given the shipping services provided to third party sellers. I have had several occasions where an overnight package was scheduled to be delivered on Saturday with that option not even given in the services provided by Amazon.

The only option I have seen, nicely provided by other sellers, is to manually turn off overnight and 2nd-day shipping services late in the week, and turn them back on Saturday night or Sunday. This is not only a pain, it is prone for mistakes to be made.