Acorns and Buds
As you can see, the acorns on this chestnut oak was an extension of the current growth. So we can say the acorns on chestnut oak are born and mature on the current years wood. This is common with white oaks (click here for example). On red oaks the acorns are born the year before and when they mature they are maturing on last years wood (click her for an example).