Subtract 7 days from current date

Question

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         


        

Answer 1

If you're running at least iOS 8 or OS X 10.9, there's an even cleaner way:

NSDate *sevenDaysAgo = [[NSCalendar currentCalendar] dateByAddingUnit:NSCalendarUnitDay
                                                                value:-7
                                                               toDate:[NSDate date]
                                                              options:0];

Or, with Swift 2:

let sevenDaysAgo = NSCalendar.currentCalendar().dateByAddingUnit(.Day, value: -7,
    toDate: NSDate(), options: NSCalendarOptions(rawValue: 0))

And with Swift 3 and up it gets even more compact:

let sevenDaysAgo = Calendar.current.date(byAdding: .day, value: -7, to: Date())

Answer 2

Swift 3

Calendar.current.date(byAdding: .day, value: -7, to: Date())

Answer 3

FOR SWIFT 3.0

here is fucntion , you can reduce days , month ,day by any count like for example here , i have reduced the current system date's year by 100 year , you can do it for day , month also just set the counter and store it in an array , you can this array anywhere then func currentTime()

 {

    let date = Date()
    let calendar = Calendar.current
    var year = calendar.component(.year, from: date)
    let month = calendar.component(.month, from: date)
    let  day = calendar.component(.day, from: date)
    let pastyear = year - 100
    var someInts = [Int]()
    printLog(msg: "\(day):\(month):\(year)" )

    for _ in pastyear...year        {
        year -= 1
                     print("\(year) ")
        someInts.append(year)
    }
          print(someInts)
        }

Answer 4

Swift operator extension:

extension Date {
    
    static func -(lhs: Date, rhs: Int) -> Date {
        return Calendar.current.date(byAdding: .day, value: -rhs, to: lhs)!
    }
}

Usage

let today = Date()
let yesterday = today - 7

Answer 5

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)!
  }
}