Description
Use PSCIncDayEx to increment or decrement given Date on the NumberOfDays value. ExcludeEvent is called for every added day and returns whether the added day need to be skipped (for example, if date is holiday or weekend and we only consider work days). ExcludeEvent can be nil. PSCIncDayEx returns result of the calculation, which is in the case of ExcludeEvent is nil, equals Date+NumberOfDays.
