Sorting a UITableView by a NSDate object with headers in Swift

SortedTableView.swift

extension NSDate{
    convenience
    init(inputDate: NSDate){
        let calendar = NSCalendar.currentCalendar()
        let timeZone = NSTimeZone.systemTimeZone()
        calendar.timeZone = timeZone
        let comps = calendar.components([NSCalendarUnit.Year, NSCalendarUnit.Month, NSCalendarUnit.Day ], fromDate: inputDate)
        comps.hour = 0
        comps.minute = 0
        comps.second = 0
        let returnDate = calendar.dateFromComponents(comps)
      
        self.init(timeInterval:0, sinceDate:returnDate!)
    }
}



class SortedTableView: UITableViewController {
	var sortedArray: Array<AnyObject>?
	var sections: NSMutableDictionary?
	var mealArray: NSMutableArray?

	override func viewDidLoad() {
		super.viewDidLoad()
		mealArray = NSMutableArray()

		mealArray?.addObject(["meal": "banana", "date": NSDate()])

		for object in mealArray! {
			let dict = object as! NSMutableDictionary
			if let exists = dict["date"] {
				let date = NSDate(inputDate: exists as! NSDate)

				var eventsOnThisDay = sections?.objectForKey(date)
				if eventsOnThisDay == nil {
					eventsOnThisDay = NSMutableArray()
					sections?.setObject(eventsOnThisDay!, forKey: date)
				}
				eventsOnThisDay!.addObject(dict)
				let unsorted = sections?.allKeys

				self.sortedArray = unsorted!.sort({ $0.date.compare($1.date) == .OrderedAscending })
			} else {
			}
		}
	}
    
    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        if mealArray?.count == 0 || mealArray == nil {
            let label = UILabel.init(frame: self.view.frame)
            label.textColor = UIColor.whiteColor()
            label.text = "No meals"
            label.tag = 6
            self.tableView.separatorStyle = .None
            label.textAlignment = .Center
            self.tableView.backgroundView = label
            return (self.sections?.count)!
        }
        
        self.tableView.separatorStyle = .SingleLine
        self.tableView.backgroundView = nil
        return 1
    }
    
    
    override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        
        if(mealArray == nil){
            return 0
        }else{
            
            let date = self.sortedArray![section] as! NSDate
            let events = self.sections?.objectForKey(date)
            return (events?.count)!
        }
        
        
        
    }
    override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        let formatter = NSDateFormatter.init()
        formatter.timeStyle = .NoStyle
        formatter.dateStyle = .MediumStyle
        
        return formatter.stringFromDate(self.sortedArray![section] as! NSDate)
    }

    
}