Is this a windup or a genuine post? It is the most ridiculous itinery that I have seen! Are you arriving from the States with jet lag? What time of year are you travelling?
The catamaran from Hvar to Dubrovnik leaves early morning and arrives at lunchtime but only runs in the summer. You will then have a half day here.
Dubrovnik to Zadar. How are you proposing to get between the two? There are no trains so it is car hire, bus or fly. There are no direct flights so that isn't an option. The bus takes c 8 hours so it will take you all day then you are heading out the following morning?
You need to do some online research or read guide books and look at a map to prioritise what you want to see, as without knowing your interests or budget, we cannot be expected to plan your holiday for you! I would suggest that if you are flying into Split, that you stay on the mainland and work your way north from there as that is realistically all you will have time to cover. Come back with more focussed questions once you have covered the basic research.