At least an hour. I would go do something and then come back to it to see what your prize is.
about 2 hours
It lasts for an hour and a few minutes, do NOT sit and wait because it takes a looooong while, just watch T.V while you wait.
About an hour or 30 minutes. ( I wonder why they made it sssssoooooooo long)!
I am a creator from neopets and it will be an annual event.