Explanation
The recommended way to calculate an account based forecast for the next 13 months in the formula builder is to create separate formulas for periods 1-12 and period 13. This is because the formula builder allows you to create different formulas for different period ranges based on theforecast display duration. For example, if the forecast display duration is 13 months, you can create up to 13 formulas, one for each month. You can also create a single formula for all 13 months, but this may not be as accurate or flexible as creating separate formulas. By creating separate formulas, you can use different fields, functions, and operators to calculate the forecast for each month based on your business logic and requirements1. References: Build Formulas to Calculate Forecast