I have a package I ordered from Amazon and they decided to send it Next Day Air Saver, I'm in Pa, it's coming from AZ. Now first off I'm not asking because I want to know when my package will specifically arrive, it'll get here when it gets here. Just curious how it works. Here's the tracking number if anyone wants to check it out: 1ZXX31291332182294. I know all the digits have a specific meaning, I've never seen XX in a tracking number, whats the relevance?? So anyway I know w/ with NSA Saver It should get it between 3-4pm/end of day. Usually I get deliveries around 11am. But my package arrived in KY around 1am. So I don't see the package making it from KY to Philly to West Chester in time. So do you think that another truck will be dispatched to my area for a later round of deliveries (I'm in Royersford Pa, all my packages get routed through the West Chester hub) Or do you think it'll arrive in time to be put on the truck in the am? Not sure if multiple trucks go out for the same route throughout the day or if it's just one truck for the route and thats it?? Thanks for any input!!! Again just curious how it all works.