Four sector days pop up every now and again as somebody with an MBA (but no CPL) decides the lazy pilots aren't working hard enough.
After a while it becomes obvious that you can't turn a 330 (then) or 777 (now) around as quickly as a 737, especially if you have an aircraft change to the other end of the airport in the middle- which is often what used to happen.
Throw in a few late connections to wait for and crew start going out of duty hours. Then the idea is quietly shelved until the next wizzkid comes along.