the average number of active devices per the last 7 days.
On a daily basis, system computes the number of devices tah has been active for the last 7 days. Average of the present measure for report period would be WAU.
In other words, WAU is computed using moving 7 days window. For example, if the report is aggregated by days, than WAU for 2023-01-31 would show the number of devices has been active between 2023-01-25 and 2023-01-31 inclusive.