**How do I use Fiscal Years?**

By default Causal uses calendar years (January to December) for the annual aggregation in charts/tables, however if you'd like to use fiscal years, you can do that by :

- Click on the workspace menu towards the top right. Ensure you're in the Spreadsheet workspace.
- Navigate to "Use Fiscal Years", and toggle on the switch.
- Select the desired start month and naming of the fiscal years. The below screenshot shows a fiscal year from 1 April to 31 March, and the naming convention uses the "start of year", i.e. the fiscal year from 1 April 2021 to 31 March 2022 would show as FY2021 (as the fiscal year started in 2021).

### Why does my variable have decimal places even though I used the round function?

If your model has variables with uncertainties (e.g. "1 to 2" or "normal(3,1)"), Causal runs many simulations of the model, taking new samples from the distributions every time (monte carlo simulation). The round function is applied to the individual simulation results, but the average of the rounded simulations results might not always be a rounded number. For example an "input" variable with the formula "1 to 2" is a triangle distribution (left picture). If you round this variable with "round(input)", Causal will take samples from the input variable and round them. 50% of the samples will be between 1 and 1.5 and 50% of the samples will be between 1.5 and 2. So the rounded variable is a distribution where 50% of the values are 1 and 50% of the values are 2 (right picture). The average value is 1.5, even though the individual simulation results never have the value 1.5.

### Uncertain values change when I refresh the model.

Causal uses Monte-Carlo simulations for uncertain values which is why refreshing the page may cause the values to change.

### Does Causal support circular references?

No, Causal doesn't support circular references for the following reasons:

- A deliberate circular reference, with iterative calculation enabled, may hide accidental circularity.
- A circular reference calculation may not converge to a solution. For
example, B3: =B3+1 grows every time the worksheet is recalculated (by
the number of iterations in the
*Enable iterative calculation* option).
- The solution may not be stable, meaning that it may change each time the worksheet is recalculated.

### I have two variables, one broken down by categories, and one without categories. If I add them together, the results are not what I expect?