New York Fashion Week opens the international season each February and September. It’s the most commercial of the Big Four — the home of American sportswear and ready-to-wear — and it’s also the oldest: the very first fashion week was held here in 1943.
When it runs
New York shows first each season — in September for the following Spring/Summer, and in February for the following Autumn/Winter — before the calendar moves on to London, Milan, and Paris.
What defines it
New York is the commercial engine of the calendar, historically defined by American sportswear, wearable ready-to-wear, and a strong sense of the market. It was established in 1943, organised to give American buyers and press an alternative to Paris during the Second World War — and in doing so it made New York a fashion capital.
Sources: New York Fashion Week — Wikipedia · Facts summarised in our own words; text under CC BY-SA where sourced from Wikipedia.