How to set 1 excused/unexcused lesson for every 3 tardies

If you need a student to have 1 excused/unexcused lesson after 3 tardies, this setting can be configured in the Class Book Settings. In the section Student Attendance, under "Tardy and early departures count as", you need to enter 0.33 lessons (3 tardies = 1 lesson):

After applying this setting and marking the tardy as an excused lesson, the student's attendance will appear accordingly:

More guides: Summary of tardies and early departures