Swift days between two NSDates

Question

I'm wondering if there is some new and awesome possibility to get the amount of days between two NSDates in Swift / the "new" Cocoa?

E.g. like in Ruby I would do:

(end_date - start_date).to_i

Answer 1

Nice handy one liner :

extension Date {
  var daysFromNow: Int {
    return Calendar.current.dateComponents([.day], from: Date(), to: self).day!
  }
}

Answer 2

let calendar = NSCalendar.currentCalendar();
let component1 = calendar.component(.Day, fromDate: fromDate)
let component2 = calendar.component(.Day, fromDate: toDate)
let difference  = component1 - component2

Answer 3

  func completeOffset(from date:Date) -> String? {

    let formatter = DateComponentsFormatter()
    formatter.unitsStyle = .brief

    return  formatter.string(from: Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second], from: date, to: self))




}

if you need year month days and hours as string use this

var tomorrow = Calendar.current.date(byAdding: .day, value: 1, to: Date())!

let dc = tomorrow.completeOffset(from: Date())

Answer 4

Here is the answer for Swift 3 (tested for IOS 10 Beta)

func daysBetweenDates(startDate: Date, endDate: Date) -> Int
{
    let calendar = Calendar.current
    let components = calendar.components([.day], from: startDate, to: endDate, options: [])
    return components.day!
}

Then you can call it like this

let pickedDate: Date = sender.date
let NumOfDays: Int = daysBetweenDates(startDate: pickedDate, endDate: Date())
    print("Num of Days: \(NumOfDays)")

Answer 5

Swift 3. Thanks to Emin Buğra Saral above for the startOfDay suggestion.

extension Date {

    func daysBetween(date: Date) -> Int {
        return Date.daysBetween(start: self, end: date)
    }

    static func daysBetween(start: Date, end: Date) -> Int {
        let calendar = Calendar.current

        // Replace the hour (time) of both dates with 00:00
        let date1 = calendar.startOfDay(for: start)
        let date2 = calendar.startOfDay(for: end)

        let a = calendar.dateComponents([.day], from: date1, to: date2)
        return a.value(for: .day)!
    }
}

Usage:

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd"
let start = dateFormatter.date(from: "2017-01-01")!
let end = dateFormatter.date(from: "2018-01-01")!

let diff = Date.daysBetween(start: start, end: end) // 365

Answer 6

Swift 3.2

extension DateComponentsFormatter {
    func difference(from fromDate: Date, to toDate: Date) -> String? {
        self.allowedUnits = [.year,.month,.weekOfMonth,.day]
        self.maximumUnitCount = 1
        self.unitsStyle = .full
        return self.string(from: fromDate, to: toDate)
    }
}