I went and picked my most ripe pod, and one from last year.
Cut them open. Old seeds still seem good, but I wonder if the embryo is actually still there. Notice the hole in the center of the cut open seed. For some woody seeds, if the embryo shrinks down creating an air space inside the seed, it's okay. But for most, the embryo is dead.
This season's seeds are ready to plant, if you so choose. When I split the pod on one side, and carefully opened it, half the seeds were completely loose and wanted to fall out. Detachment is a definite sign of being
post ripe. They are also changing color. If you want to get any sprouting this year, plant them now, before the seed coat hardens. If they sprout, I am guessing you will need to keep the seedlings actively growing inside through the winter, though. Seedlings that don't normally sprout in the fall usually don't have the built in mechanisms to survive the ensuing winter. If you plant to plant later, it would be best to keep the seeds contained in the pod, where they will dry more slowly, until they get hard on their own.