Parsley and Thyme Harvesting Period

I have recently begun to grow parsley and thyme in my garden. How long should I continue to harvest these herbs? Can I continue until to use it until the snow comes? Is there a point in the season after which these herbs are no longer edible?

Parsley can be harvested until the killing frosts arrive. After a killing frost the leaves wilt and become mushy and die.
The same is true for thyme, although sometimes is it is possible to use still green leaves even after a snow fall. Thyme leaves are tougher than parsley and can restand a few degrees of frost before succumbing.