In the input box for holidays, you decide how date-limited lessons are proportionately calculated. In the following, simple examples will explain what is meant by this:

- count all weeks (even holidays)

When a school year lasts for 40 weeks and lessons take place during 20 weeks, the lesson is multiplied by factor 0.5 (20/40). A one-hour lesson therefore counts for 0.5 value units.

This means that without any exception, every week between the beginning and the end of the school year is counted as an active week. This counting method is similar to the first selection “count all weeks (even holidays)”.

This option for calculating the values takes all the weeks into account which have at least one day on which a lesson can take place. In other words: Full holiday weeks are not counted. This counting method corresponds to the second selection: “count active weeks (only calculate school days)”.

- count active school days (calculation of yearly weeks using single days

If there were also single free days in this time range (i.e. public holidays or half-holiday weeks), it could also be taken into account that in the time range in which lessons are taking place (18 weeks) there are additional days without lessons. Let’s assume that there are 4 additional free days. The factor to multiply would then be calculated as follows: 18 weeks of 5 days each minus the additional 4 free days / number of days in the school year.

(90 – 4) / (40 *5 – 10-4) = 86 / 186 = 0.46

The lesson would then only be worth 0.46 units. This counting method corresponds to the third selection “count active school days (calculation of yearly weeks using single days)”.

Since in this method it is not necessary that the number of school weeks is wholenumbered, the effective weeks are also displayed. The display immediately reacts to the selected option. In the example the effective number of weeks of the school year is 37.20.

Which of the three methods is now the right one? None is “more right” than the other. You decide yourself (or the legislator decides for you) which method you want to apply.

Considering that the value of the lesson does NOT take the position of the periods in the timetable into account, the third method (count active school days) is the one which comes closest to reality. Due to non-whole-numbered effective weeks, however, it is the most difficult to understand and also the most difficult to explain to the teachers. The second method – count active weeks – is the one used very often because it is more precise than the first method and the values remain clearly comprehensible.