As you can do with substitutions, you can also generate absence statistics in the absence window. Select the respective time range and filter by certain criteria such as the reason of absence.
Via "Grid adjustment" you can show the "Cancelled days" and "Absence days" columns.The "Absence days" show the number of days of absence. The "Cancelled days" column - like the statistics of the same name - shows how many actual cancelled days were the consequence. If a teacher does not teach on a certain day, this day counts as absence day but not as cancelled day, as the example below shows.