Full groove are the oldest, followed by the 3/4 groove, followed by the 1/2 groove followed by the celt. And that's not set in stone. (Hee hee, see what I did there?
) As far as actual dates, that would be quite difficult to determine for an out of context tool. There's quite a bit of overlap, generally in the area of 1000 to 1500 years. And the various patterns were used for 2-5 thousand years before a change would start.
You'd have to find something organic in the same layer to test to narrow it down.