A Collective Schedule describes the employees' expected working hours over a week.
It comes in two shapes:
The Pattern this Collective Schedule implements. Depends on the Shape.
Should half-days be discriminated? In other words, should shifts belong to half days rather than just the day itself?
The date (included) from which this Collective Schedule is applicable. Must be left null for the very first Collective Schedule of a Working Time Arrangement.
The date (included) from which this Collective Schedule is no longer applicable. Is null for the last Collective Schedule of a Working Time Arrangement. Can not be modified as its equal to the day before the next applicable Collective Schedule for this Working Time Arrangement.