Schedules typically remain consistent unless one of the following happens: You move to a new line of business (which happens as you progress through the tiers), you complete a shift bid (which does not happen often), or if there is a business need requiring the change. In all of these situations, there is no guarantee you will be given a weekend off or an early schedule; however, the longer you are with the company, the better the chance you will have this opportunity at some point.