There is an Action Type to "Enable Saturday Delivery", but to use this action well, we need a criteria that basically says "If today is Friday and ______ premium shipping service was selected". I understand this may be difficult because you'd constantly need to check the date and reprocess the rule, so perhaps this is something that is triggered when doing the create and print label command? Or if that's impossible, perhaps the ability to say "if order date is between Thursday 3pm and Friday 3pm" or something of that nature to dial in on which orders will generally be shipped on a Friday, so we can selectively add the Saturday delivery option to orders that a customer has requested a shipping service where they expect it will be delivered on a Saturday.
Since this option doesn't exist, we have to either pay the extra $15 Saturday delivery charge every order, or else manually enable it for certain orders when shipping out on a Friday. Usually this results in very angry customers because we forgot to check the box. My business sells parts that fix peoples' cars. They're not happy when they don't get their parts on Saturdays and have to miss work Monday because of a checkbox ><