private void Calculate()
        {
            if (Birthdate.CalculateAge(BDate) > 135)
            {
                MessageBox.Show("Error! You are too old!");
            }
            else if (BDate.CompareTo(DateTime.Today) > 0)
            {
                MessageBox.Show("Error! You don't exist yet!");
            }

            else if (BDate.Month.CompareTo(DateTime.Today.Month) == 0 && BDate.Day.CompareTo(DateTime.Today.Day) == 0)
            {
                MessageBox.Show("Happy Birthday! Enjoy your special day!");
                _bDate.CalculateAge();
                _bDate.Westerngoroscope();
                _bDate.Chinesegoroscope();

                OnPropertyChanged("Age");
                OnPropertyChanged("WGoroscope");
                OnPropertyChanged("CGoroscope");
            }
            else
            {
                _bDate.CalculateAge();
                _bDate.Westerngoroscope();
                _bDate.Chinesegoroscope();

                OnPropertyChanged("Age");
                OnPropertyChanged("WGoroscope");
                OnPropertyChanged("CGoroscope");
            }
            Thread.Sleep(1000);
        }