By Pat Loeb

PHILADELPHIA (CBS) — Philadelphia’s effort to become a fashion center continues with its third annual Fashion Week, this fall. City officials on Wednesday announced the dates for this year’s edition and introduced a new element to the event.

Five years ago, Simmons Research declared Philadelphia the nation’s sweat suit capital. This year, the city was named to the list of best shopping cities by Forbes, CNBC and Lucky magazine. City representative Melanie Johnson says events like fashion week — dubbed the Philadelphia Collection — have helped.

“People are taking notice,” Johnson says. “We are really dressing very well. And you are going to be quite surprised at the number of events and the people who’ve decided to become a part of the Philadelphia Collection 2012.

This year’s Fashion Week will take place September 13th through the 20th, and Mayor Nutter announced the city would be part of the worldwide “Fashion Night Out,” for the first time on September 6th, when stores will stay open until 11 p.m.

“Philadelphia is able to show the world that we are a city that’s ready to assume its rightful place among the fashion capitals of the world,” Nutter says.