Last year my wife only came to the show with me for a few days. For one of
those days she put on the wrong day's wristband, and we didn't realize it
until almost the end of the day. We'd gone through numerous gates
throughout the day and no one questioned it. Maybe it was because she was
with me and I had a full week pass wristband on, but who knows? I'd suggest
the OP buy the wristband for the next day, and try getting in when he
arrives the day before. The worst that could happen is that they'll stop
you and you'll have to buy another band.
Scott Wilson

On 23-Jun-2006, wrote:

Paul

Talked to the Airventure Office. You have to have the wrist band for
that
day of admission. No other days pass wrist band. Gates are manned
24 hours. The whole airport has security guards all night.