How To Get Day Before And After In Swift

extension Date {
    var dayAfter: Date {
        return Calendar.current.date(byAdding: .day, value: 1, to: self)!
    }

    var dayBefore: Date {
        return Calendar.current.date(byAdding: .day, value: -1, to: self)!
    }
}

let tomorrow = Date().dayAfter
let yesterday = Date().dayBefore