At room temp apples will convert some of their starches to sugar- a week should accomplish this, but really green apples are only useful for cooking, IMO.

I've had these small apples sitting at room temperature for two weeks, and just tried one. It was edible, no sourness at all...but not as sweet as organic Gala's I've bought at the local coop. Strangely (but very nice) it had a very distinct cinnamon taste. I wonder if this was the result of the early picking or is this an unusual Gala apple tree.