September is when fashion gets serious. As the industry heads from New York to London, Milan, and Paris for Fashion Month, brands are setting the agenda with new collections, collaborations, and store openings in between what’s taking place on the runway.Starting the month strong is Gap, which introduced the “GapBag” collection designed by Reed Krakoff. From fall wardrobe staples to the season’s buzziest designer team-ups, these are the launches to know. Below, follow along with September’s can’t-miss fashion moments.Christian FerrettiWho: GapWhat: New handbag collectionWhere: Online at gap.com and in select Gap stores starting September 8Why: What if your favorite pair of jeans became a handbag? Gap has the answer. The “GapBag” collection—the debut line designed by Reed Krakoff, the brand’s executive director of accessories—translates five-pocket denim, the Arch Logo hoodie, and other signatures into a lineup of totes, satchels, crossbody bags, and pouches. The collection centers on five silhouettes, including the Five-Pocket Tote, Hoodie Tote, Favorite Tote, Crescent Bag, and oversize Shoulder Bag, in denim, canvas, faux suede, fleece, and playful prints.“Gap has been part of my life, as it has for so many people around the world, for as long as I can remember,” Krakoff said in a statement. “For more than five decades, Gap's design language has shaped the way the world dresses. The GapBag Collection draws on that legacy: iconic American style, simple, never plain, built on the idea that form follows function and that luxury is the coming together of style, utility and design. The five-pocket tote series is emblematic of that unmistakable Gap style, in its broken-in washed denim, jean-stitch detailing and signature metal shanks. It is made for everyone, every day, every occasion.”