As a resource manager, I make updates in daily or weekly batches based on project timeline slippage and other continuously evolving conditions among my projects. When I work through updates, I may make changes that lead to downstream resource impacts that aren't viable, and as such need to revert to my previous resource schedule to try again. As such, I need the ability to save a version of my entire resource schedule before working on adjustments and need to be able to revert to that state; this could also be accomplished with a new type of draft booking that doesn't eliminate the previous booking until I confirm.