Choose how the report should calculate the values. By default, the system will consider only the stayed nights in the range of dates used as filter. For example, if you are querying the report for a specific month, say March, a reservation with stay dates between March and April will have its values adjusted proportionally with the amounts for March. Instead, if you wish to base the data on the check-in date, maybe to get an idea of the effective incomes, in the above example a reservation with a check-out date exceeding the end-date in the filters will still be considered in full with no average calculation.