Periodically, we need to create a copy of the current data.
For example, we may fill the forecast data with actual data for past months and with budget data for future ones.
Or, we may create several budget and forecast versions to make a decision about right numbers.
You may copy data between periods and categories using the data_management worksheet:
Just right-click on the desired cell and choose the operation (the menu is dynamic):
For example, we may use these operations to prepare forecast data for this case.