You can pick it and it will be fine until Halloween. I have heard that in the northern states they can't get overripe and can be left on the vine until you want them, but in the southern states they need to be picked when they are ripe or they will rot. I like to pick them when they are ripe so that they aren't left on the ground where bugs and animals can get to them. I have one that is completely orange and I am going to pick it in a few days. I also like to think that by taking the ripe pumpkin off the vine it frees up energy to vine to produce more pumpkins. I suggest you look up the process of curing just to be extra sure your pumpkin will last.

I think that as long as the pumpkin is completely mature it should come off. If it is left on the vine bugs can damage it, and it may go bad in the heat and everything. As long as it has a hardened rind and you keep it somewhere dry, airy, and warm it should keep until Halloween.

ok thanks guys