It seems that I can\'t subtract 7 days from the current date. This is how i am doing it:
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:N
Swift 4.2 iOS 11.x Babec's solution, pure Swift
extension Date { static func changeDaysBy(days : Int) -> Date { let currentDate = Date() var dateComponents = DateComponents() dateComponents.day = days return Calendar.current.date(byAdding: dateComponents, to: currentDate)! } }