This idea always struck me as a little childish. Do developers who are creative enough to make useful tools need to be constrained to some one-week window in which it's allowed to do so?
No, but in the real world of deadlines, collaboration with teams that have their own different schedules, priorities, etc., they very often need a one week window not constrained but instead opened such that they can actually get something done about items in the important but not urgent quadrant.