Best practice for passing NSDateComponents to UILocalNotification?

Question

I'd like to pass an NSDateComponents object to my UILocalNotification object's userInfo property. What is the most elegant way of doing this?

I'm working with EKReminders and am passing their dueDateComponents (which are of type NSDateComponents.) I'm also passing two Strings, so I'm thinking maybe I'll just pass the NSDateComponent's description property. (I can't pass the NSDateComponent itself because it's not a valid 'property list type') When I receive the local notification I need to make an NSDateComponents again back out of the String. I'm doing that with the following code, but I'm not sure it'll always work (for every locale?) because I don't know whether the dueDateComponents always has the same format as below...

Is this really the best/most stabile way of passing NSDateComponents?

let duedatestrTime = "2016-10-01 01:00:00 +0000"

// MARK: date utilities
extension String {
    func toDate() -> NSDate? {
        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss Z"  // IS THIS RELIABLE? DO I KNOW THAT EKReminders.dueDateComponents ALWAYS HAVE THIS FORMAT? IF NOT IT'LL RETURN NIL... 
        return dateFormatter.dateFromString(self)
    }
}

extension NSDate {
    func toNSDateComponents() -> NSDateComponents {
        let unitFlags: NSCalendarUnit = [.Day, .Month, .Year, .Hour, .Minute]
        return NSCalendar.currentCalendar().components(unitFlags, fromDate: self)
    }
}

let x = strTime.toDate().toNSDateComponents()

Answer 1

NSDate is a valid type to use. Why not just convert the components to an NSDate to pass it in, and then convert it back to components on the way out if that's what you need?