As with all things, your "timing" - meaning day, actual lateness and whomever is manning the door, will then determine your fate. Having said that, if you're with a group and they are able to go in without you, you may be able to catch up. If you and your entire party are late, they may bump you and let in the next guests.
Not sure. I was late, but my friends checked in at the correct time. They let me in though!
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