Early. Aim to be there for 9am and have a plan of which rides you really want to do first
Depends on what all you want to do. If your going for the rides get there before they open. If you prefer the night time stuff late evening for free parking.
At least 20 minutes before it opens.
Early afternoon it's best if you are planning on staying for the night show. If you go too early you could be too tired for that.
Late afternoon, early evening also works reasonably well due to the summer heat and mid-day crowds. The August sun is brutal.
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