While this recipe computes an annual ETR for the sake of simplicity, the formula can be easily modified to account for any range of time. To do this, remove the row where the __Year variable is set to 2019. Then, set the __StartPeriod variable to the minimum date within the current context using the MIN or MINX functions. Similarly, set the __EndPeriod variable to the maximum date within the current context using the MAX or MAXX functions. To see an example of how this is done, please see the next recipe, Computing absenteeism.