People, people. I was in the Royal Shakespeare Company for many years, and have written novels. Language is ever changing like the roads of the planet, but most remain the same for convenience and posterity and nostalgia. That has not stopped the US (some 500 million) changing orientATed into oriented, the former still spoken by a modest 65 million Britons. Some would say the majority are correct. Two weeks' notice (correct) is one of those tricky language anomalies which is well documented and must be learned. We cannot decide there are more than 5 vowels because it is an hour or an MA. We spell yacht and xylophone as we do because they have evolved that way. There are rules governing spelling, capitalisation, and punctuation too. I agree with Pammi and highly recommend Lynne Truss's book (notice the split infinitive - not a hard and fast rule anymore). The ridiculous pitfalls created by poor punctuation are amusing, but also a warning. Play around with language and we're back up the tower of Babel. Those of you citing the genitive sense are correct, and those blinkered by the 'possession' of the notice must remember the length of notice is denoted by the time. It is not possessed by the two weeks but it is shaped by them in the sense and meaning. It is the same as The Hundred Years' War. Take away the 'Hundred Years' and it's just The War. Those citing the missing 'of' are correct in approach, the apostrophe is not replacing the word 'of' specifically, but realises and displays the connection between the weeks and the notice. There are many ways of saying it...the worker's notice was two weeks long, he was given notice of two weeks, the notice he gave was of two weeks in length (the weeks possess the length there) The history of the grammar will tell the unsure, go to the Oxford English Dictionary to be certain - those guys think these things inside and out, so you can be sure everything's been considered. Stick to the smallest rules and we're all singing from the same song sheet. 'Look after the pennies and the pounds will look after themselves'. To some, the oriented person is of the Orient. To others Captain Kirk, and then Picard, should have 'gone boldly', and the debates continue with lessening detriment to understanding until many thousands went to see 'Two Weeks Notice' without thinking about the missing apostrophe. We must continue the debate, however trivial it may seem to most, and I applaud you all for your two minutes' toil reading this epistle.