It is not an assumption that the park will be flooded with day guests at 7pm, it is a fact. If the park closes at 7pm day guests will stay until the last minute (which they are entitled to do so) The concerns of everyone on this thread are valid. The chaos of people still in the parks trying to leave (and who knows how long that will take) while the partygoers are trying to get in and enjoy the party are enough to warrant all the complaints to Disney to have them clarify all the confusion. Just as the day guests are entitled to stay until 7pm, party goers are entitled to have their time in the park without having to worry about losing an hour or so waiting for the daytimers to leave before the festivities start. Which is exactly what Eric from the Exective Offices told me, and I quote, "No party activites will start until all day guests are cleared from the park, so don't worry, they won't be able to enjoy the festivities." Remember, they are entitled to a 10 hr day to play, party goers are only entitled 5 and to take an hour to clear the parks leaves only 4 hrs of party time. Those who bought tickets bought them for the festivities, not for stuff you can do any other time of the day.