All the banks are trying to push their online banking services, and IMHO the state of online banking today has improved dramatically over the past few years. I remember when Bank One (which is now Chase) took their online banking site off-line a few hours in the early AM every weekday, and even longer on the weekends - but that's changed. I used to detest Wells Fargo's site back when I was on dial-up, since one of the first things that happened when connecting was that it would send down a fresh certificate file, which took a while at 28.8 kps ;-)
Obviously the technology investment is offset by the potential staff reductions or other similar cost-reduction efforts. But for the typical business with employees, payroll & benefits amount to 2/3 of its expenses, so this area is an easy target for cost reductions.
But what's the deal with "bank business days" - ?? What a thoroughly antiquated concept. If I can transfer funds and make payments at the click of a mouse, why is it that a deposit made on Saturday or Sunday, whether ATM or drive-thru or even walk-in, doesn't get posted until Monday? With the advent of electronic check processing, banks being empowered by the so-called Check 21 initiative, the time has come for the bank business day concept to be retired.