What is the rolling budget and its uses?

Method in which a budget established at the beginning of an accounting period is continually amended to reflect variances that arise due to changing circumstances.

The budget which is continuously updated for a specific period of time in future. Each time when it is updated a new period is added in future and one earliest period is dropped from budget plan.

For example a budget is prepared for12 months. when one month passed it is updated up to13 months and1st month of last budget is dropped from the plan. so it will always be for a period of12 months rolling forward.