Issues with dates in doctype "Student Attendance"

[clevermind-me]

If you select a date when there are no classes, this is not an error and even in the monthly attendance report and in the Student Attendance, there will be “Attended” next to the student on this day.
However, if you select a date on which there is a class, but do not select the class itself, the “Attended” status will also appear, but there will be no data on its attendance in the class itself. See on 10/30

It may be better if:

1. The date when there is no class will not be available for selection.
2. If there is a class on the selected date, its selection is mandatory.