It's a bit busy then. The lines can get long during that time, and the parks were a bit crowded. You are checking in on the 13, and leaving on the 16th? If you have a full 3 days maybe, but if you're a family of adults/teens who want to ride the bigger rides, and are not there just for the toddlers side of things you might be pressed for time. Considering shows, and such, and the park hours are not real late there, I believe california adventures side closes at 8, and also opens later than the magic kingdom side, and then the magic kingdom side depending on what day may close at 9, or 10 check the calendar hours listed is best. Honestly I think you may find yourself rushing through or commandoing it if you're trying to see mostly everything. I suggest going to their website, and looking at the rides list, attractions/shows, and such see what ones are most important to you and make a plan of what means the most for you to get to see, and do make those your top items then see where you are after that might be best, so you can base your time frame on that.