If you're doing standard 7 day listing, the easy method is probably use Auto-Relist. You would initially schedule 4 listings for each of the 7 days of the week with one Auto-Relist profile for the entire group if they aren't BIN, i.e. they always end at specific day and time. If they are BIN and could close at any time (when bought), you might have to do 28 Profiles to cover the 7 x 4/day schedule (to keep them ordered). However, the work to automate is probably less intensive than constant scheduling hassle for 28 each week.
I may be overlooking something even simpler with Auto-Relist or a case I haven't thought about, but hope those ideas give you some direction to possible solution.
Danno
Oh....and if you're using less than 7 day, the later method should still fire them off at the specific day and time no matter what format (BIN or not).