If the skin is hard enough that you can't easily puncture it with a fingernail, they should be mature enough to cure and store.

If not, they'll start to shrivel from moisture loss. You'll know pretty soon, within about a week or so at most.

When I have immature ones that aren't going to make it, I just roast them up with Mrs. Dash and oil and eat them that way. They're sort of halfway between a summer squash and a winter squash at that point, but taste great cooked like that. Actually, my dog LOVES roasted squash of any kind, so it's never a problem at my house, he will always eat the excess, and I've found it to be quite a healthy treat for him.