Find the Zodiac sign using Date of Birth in C# .Net

This Way:

<form id="form1" runat="server">
    <div>
        Date of Birth
        <asp:TextBox ID="txtDateOfBirth" runat="server" /><br />
        <asp:Calendar ID="Calendar1" runat="server" OnSelectionChanged="DateChanged"></asp:Calendar>
        <asp:Label Text="Zodiac" runat="server" />
        <asp:TextBox ID="txtZodiac" runat="server" /><br />
        <asp:Button Text="btnFindZodiac" OnClick="FindZodiac" runat="server" />
    </div>
    </form>

C#:

protected void DateChanged(object sender, EventArgs e)
        {
            this.txtDateOfBirth.Text = Calendar1.SelectedDate.ToShortDateString();
        }
        protected void FindZodiac(object sender, EventArgs e)
        {

            string[] date = txtDateOfBirth.Text.Split('-');
            Findzodiac(date[1], Convert.ToInt32(date[0]));

        }

        private void Findzodiac(string month, int day)
        {
            string str = string.Empty;
            if (((month == "Mar") && (day >= 21 || day <= 31)) || ((month == "Apr") && (day >= 01 || day <= 20)))
            {
                txtZodiac.Text = "Aires";
            }
            if (((month == "Apr") && (day >= 21 || day <= 31)) || ((month == "May") && (day >= 01 || day <= 21)))
            {
                txtZodiac.Text = "Taurus";
            }
            if (((month == "May") && (day >= 21 || day <= 31)) || ((month == "Jun") && (day >= 01 || day <= 21)))
            {
                txtZodiac.Text = "Gemini";
            }
            if (((month == "Jun") && (day >= 22 || day <= 31)) || ((month == "Jul") && (day >= 01 || day <= 22)))
            {
                txtZodiac.Text = "Cancer";
            }
            if (((month == "Jul") && (day >= 23 || day <= 31)) || ((month == "Aug") && (day >= 01 || day <= 22)))
            {
                txtZodiac.Text = "leo";
            }
            if (((month == "Aug") && (day >= 23 || day <= 31)) || ((month == "Sep") && (day >= 01 || day <= 21)))
            {
                txtZodiac.Text = "Virgo";
            }
            // in the same way you search fot other
        }

 I have refer this Zodiac dates from this website

http://answers.yahoo.com/question/index?qid=20091204113202AAMOyBs

Aries (21 March-20 April)
Taurus (21 April-21 May)
Gemini (22 May-21 June)
Cancer (22 June-22 July)
Leo (23 July-22 August)
Virgo (23 August-21 September)
Libra (22 September-22 October)
Scorpio (23 October-21 November)
Sagittarius (22 November-21 December)
Capricorn (22 December-20 January)
Aquarius (21 January-19 February)
Pisces (20 February-20 March) 

i have find the zodiac date till virgo you can add the sode for other month in using if condtion.