Name: bitmaskValidity
A validity may be made up of a bitmask validity. This kind of validity is defined by an array of 0 and 1's, one for each day of its duration. A one encodes that an operation is going to take place on the day its slot represents, a zero encodes that it does not.
Name: operatingDayValidity
A validity may be made up of an OperatingDayValidity. This kind of validity may be used in early planning stages, when the precise dates are not clear yet. It allows describing that an operation takes place on a certain day of the week.
