Rotating Schedule VBA for highlighting cells in named range

I have a calendar that can can be cycled through by year. I want to be able to fill four cells in the range, then leave four alone, then highlight four until the end of the range. I'd also like to be able to pick a starting point or have it move correctly each year (for 2015, the first 4 days highlighted should begin on the third.) I have code to run through each cell in the range that highlights every fourth cell. But I'm having trouble with the logic and taking it any further.

I also think I'll have an issue skipping the greyed out days on the calendar. Any advice woul be great.

The worksheet is attached.