In the reports, how to take all days into accounts in the calculation the Average Daily Hours, including the ones with no entry ?

In the reports, how to take all days into accounts in the calculation the Average Daily Hours, including the ones with no entry ? If, for exemple, I generate a report for last week, I would like the average daily hours to be the total time of the week divided by seven, even if I haven’t had entries for all of these seven days. From what I see, the report only divides the total by the number of days for which there has been an entry.