You will find periods that still require entries to be made listed under menu item "Open period: Teachers. This list displays periods for which no teaching content has been entered and lessons for which student absences have not been checked.
You can use the 'Entry' selection field to limit the list to only those lessons where teaching content is missing or where absences are missing.
Once teaching content has been entered for a lesson it will no longer be displayed in this list.
The list will indicate optically whether absences or teaching content have been entered.
Click on the class register icon with a warning triangle in order to enter absences and on the book icon with a warning triangle in order to enter teaching content.