When you create a forecast, one of the methods you can use is to copy one of your existing forecasts. This is useful if you want to create a forecast similar to one you already have.
Click the Forecasting tab.
Click one of the following options:
Click Create from an existing forecast.
A dropdown appears for you to choose the forecast you want to duplicate from.
Select the forecast you want to copy.
Enter the name and start date, then click Create new.
You now have a copy of a forecast that you can make changes to.