import D2PDatePicker
class ViewController: UIViewController {
    
    var datePickerView: D2PDatePicker!
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        // Init DatePickerView
        datePickerView = D2PDatePicker(frame: .zero, date: Date())
        datePickerView.translatesAutoresizingMaskIntoConstraints = false
        
        // Set the Delegate
        datePickerView.delegate = self
        self.view.addSubview(datePickerView)
        
        self.view.addConstraints([
            NSLayoutConstraint(item: datePickerView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 250),
            NSLayoutConstraint(item: datePickerView, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 200),
            NSLayoutConstraint(item: datePickerView, attribute: .centerX, relatedBy: .equal, toItem: self.view, attribute: .centerX, multiplier: 1, constant: 0),
            NSLayoutConstraint(item: datePickerView, attribute: .centerY, relatedBy: .equal, toItem: self.view, attribute: .centerY, multiplier: 1, constant: 0)])
    }
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}
extension ViewController: D2PDatePickerDelegate {
    
    func didChange(toDate date: Date) {
        print(date)
    }
    
}

self.datePickerView.mainColor = .red