Whether one should use an apostrophe in such expressions as 'Ten years imprisonment' is a disputed and not very important point. Well; I'll agree that it isn't the end of the world, whichever form you use - but I still contend that "Two Weeks" is plural not possesive - and I have a lot of sympathy with -
but the word must be hyphened [ - eh? you must mean hyphenated matey...] However, "hyphened" is a completely acceptable, if somewhat outdated, form. "Hyphenated" is in line with modern usage, and I am perfectly happy to accept that (even though I would hesitate to use it myself!) I guess it has its origins on the other side of the Atlantic from my abode, and would suggest that, seeing as all-y'all US'ns have discarded various letters from the original language (like the "u" from "flavour", for instance) you are now compenating by adding redundant syllables to words like "hyphened".
