I've been flicking through Vogue again for the first time in five years because designer fashion, thanks to the sales, has become accessible: go to the third floor of Harvey Nichols in London's Knightsbridge, where there are rows of discounts at 5

0 and 75 per cent, and you can buy a tailored skirt for the price of one at Marks & Spencer.

But the latest fashion news is proof that everything comes round again: the knee length skirt is back. I must tell my mum that - and my 12-year-old daughter, who insists on rolling up her skirt into a micro, causing the headmistress to go on the warpath.Vogue's fashion diarist reports on Tiffany's "black bias-cut knee length skirt", and how "mid-thigh lengths look old" while Calvin Klein, overseeing last-minute details in New York, instructs his fitters: "raise that hem another inch - to the knee". Finally, back in London, at Helen Storey's fashion show, she writes that the tent was abuzz as foreign journalists were tipped off that the best knee-length black pencil skirt was at nearby Marks & Spencer - and has been for as long as anyone can remember.