Let me answer it in 20 seconds or less, apparently.
There are two things. First, as you rightly pointed out, you get credit for payment on the day you paid it, irrespective of how long it takes to go between your bank and the bank of card issuance. With respect to the mechanics of actually expediting it, that is very much what we're working towards with the real-time rail and real-time payments movement, so that the payment can move literally in seconds from one institution to another institution.