Country wise Date and time print using Dropdownlist in asp.net

 <asp:DropDownList ID="ddlcountry" runat="server" AutoPostBack="true" OnSelectedIndexChanged="ddlcountry_SelectedIndexChanged">
            <asp:ListItem>select country</asp:ListItem>
            <asp:ListItem Text="India,Sri Lanka" Value="India"> </asp:ListItem>
            <asp:ListItem Text="United Kingdom,"
                Value="United Kingdom"> </asp:ListItem>
            <asp:ListItem Text="France,Spain,Slovenia,Slovakia,Poland,Norway,Nigeria,Niger,Monaco,Netherlands"
                Value="France"> </asp:ListItem>
            <asp:ListItem Text="Botswana,Moldova,Latvia,Estonia,Belarus,South Africa,Rwanda"
                Value="Botswana"> </asp:ListItem>
            <asp:ListItem Text="Senegal" Value="Senegal"> </asp:ListItem>
            <asp:ListItem Text="France" Value="France"> </asp:ListItem>
            <asp:ListItem Text="Spain" Value="Spain"> </asp:ListItem>
            <asp:ListItem Text="Botswana" Value="Botswana"> </asp:ListItem>
            <asp:ListItem Text="South Africa" Value="South Africa"> </asp:ListItem>
            <asp:ListItem Text="Bahrain" Value="Bahrain"> </asp:ListItem>
            <asp:ListItem Text="Iran" Value="Iran"> </asp:ListItem>
            <asp:ListItem Text="United Arab Emirates" Value="United Arab Emirates"> </asp:ListItem>
            <asp:ListItem Text="Afghanistan" Value="Afghanistan"> </asp:ListItem>
            <asp:ListItem Text="Pakistan" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Nepal" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Bangladesh" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Myanmar" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Cambodia" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Singapore" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="China" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Japan" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Zimbabwe" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="USA" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Switzerland" Value="Pakistan"> </asp:ListItem>
            <asp:ListItem Text="Bahrain,Somalia,Saudi Arabia,Russia,Qatar,Sudan,Madagascar,Kuwait,Kenya,Ethiopia,Djibouti,Iraq,Lesotho,Burundi"
                Value="Behrain"></asp:ListItem>
            <asp:ListItem Text="Iran" Value="Iran"></asp:ListItem>
            <asp:ListItem Text="Armenia,Seychelles,Reunion,Oman,Mauritius,United Arab Emirates,Georgia,Azerbaijan"
                Value="Armenia"></asp:ListItem>
            <asp:ListItem Text="Afghanistan" Value="Afghanistan"></asp:ListItem>
            <asp:ListItem Text="Pakistan,Maldives,Kyrgyzstan" Value="Pakistan"></asp:ListItem>
            <asp:ListItem Text="Nepal" Value="Nepal"></asp:ListItem>
            <asp:ListItem Text="Bangladesh,Kazakhstan" Value="Bangladesh"></asp:ListItem>
            <asp:ListItem Text="Myanmar" Value="Myanmar"></asp:ListItem>
            <asp:ListItem Text="Cambodia,Laos" Value="Cambodia"></asp:ListItem>
            <asp:ListItem Text="Philippines,Mongolia,Macau,Indonesia,Brunei,Malaysia,Hong Kong,China"
                Value="Philippines"></asp:ListItem>
            <asp:ListItem Text="Japan,Korea" Value="Japan"></asp:ListItem>
            <asp:ListItem Text="Micronesia" Value="Micronesia"></asp:ListItem>
            <asp:ListItem Text="Papua New Guinea,Australia" Value="Papua New Guinea"></asp:ListItem>
            <asp:ListItem Text="New Caledonia" Value="New Caledonia"></asp:ListItem>
            <asp:ListItem Text="New Zealand,Fiji" Value="New Zealand"></asp:ListItem>
            <asp:ListItem Text="Argentina,Brazil" Value="Argentina"></asp:ListItem>
            <asp:ListItem Text="Cuba" Value="Cuba"></asp:ListItem>
            <asp:ListItem Text="Aruba,Puerto Rico,Paraguay,Netherlands Antilles,Barbados,Grenada,Bolivia,Chile,Dominican Republic,Guyana"
                Value="Aruba"></asp:ListItem>
            <asp:ListItem Text="Bahamas" Value="Bahamas"></asp:ListItem>
            <asp:ListItem Text="Peru,Panama,Jamaica,Haiti,Ecuador,Colombia,Canary Islands" Value="Peru"></asp:ListItem>
            <asp:ListItem Text="Bhutan" Value="Bhutan"></asp:ListItem>
            <asp:ListItem Text="Belize,Mexico,Honduras,Guatemala,El Salvador,Canada,Costa Rica"
                Value="Belize"></asp:ListItem>
            <asp:ListItem Text="Nicaragua" Value="Nicaragua"></asp:ListItem>
            <asp:ListItem Text="United States Of America" Value="United States Of America"></asp:ListItem>
            <asp:ListItem Text="French Polynesia" Value="French Polynesia"></asp:ListItem>
            <asp:ListItem Text="Samoa" Value="Samoa"></asp:ListItem>
            <asp:ListItem Text="Singapore" Value="Singapore"></asp:ListItem>
            <asp:ListItem Text="Slovak Republic" Value="Slovak Republic"></asp:ListItem>
            <asp:ListItem Text="Solomon Islands" Value="Solomon Islands"></asp:ListItem>
            <asp:ListItem Text="St Helena" Value="St Helena"></asp:ListItem>
            <asp:ListItem Text="St Kitts & Nevia" Value="St Kitts & Nevia"></asp:ListItem>
            <asp:ListItem Text="St Lucia" Value="St Lucia"></asp:ListItem>
            <asp:ListItem Text="Surinam" Value="Surinam"></asp:ListItem>
            <asp:ListItem Text="Swaziland" Value="Swaziland"></asp:ListItem>
            <asp:ListItem Text="Sweden" Value="Sweden"></asp:ListItem>
            <asp:ListItem Text="Switzerland" Value="Switzerland"></asp:ListItem>
            <asp:ListItem Text="Syria" Value="Syria"></asp:ListItem>
            <asp:ListItem Text="Taiwan" Value="Taiwan"></asp:ListItem>
            <asp:ListItem Text="Tajikistan" Value="Tajikistan"></asp:ListItem>
            <asp:ListItem Text="Tanzania" Value="Tanzania"></asp:ListItem>
            <asp:ListItem Text="Thailand" Value="Thailand"></asp:ListItem>
            <asp:ListItem Text="Tonga" Value="Tonga"></asp:ListItem>
            <asp:ListItem Text="Trinidad & Tobago" Value="Trinidad & Tobago"></asp:ListItem>
            <asp:ListItem Text="Tunisia" Value="Tunisia"></asp:ListItem>
            <asp:ListItem Text="Turkmenistan" Value="Turkmenistan"></asp:ListItem>
            <asp:ListItem Text="Turks & Caicos Islands" Value="Turks & Caicos Islands"></asp:ListItem>
            <asp:ListItem Text="Tuvalu" Value="Tuvalu"></asp:ListItem>
            <asp:ListItem Text="Uganda" Value="Uganda"></asp:ListItem>
            <asp:ListItem Text="Ukraine" Value="Ukraine"></asp:ListItem>
            <asp:ListItem Text="Uruguay" Value="Uruguay"></asp:ListItem>
            <asp:ListItem Text="USA" Value="USA"></asp:ListItem>
            <asp:ListItem Text="Uzbekistan" Value="Uzbekistan"></asp:ListItem>
            <asp:ListItem Text="Vanuatu" Value="Vanuatu"></asp:ListItem>
            <asp:ListItem Text="Venezuela" Value="Venezuela">  </asp:ListItem>
            <asp:ListItem Text="Vietnam" Value="Vietnam">  </asp:ListItem>
            <asp:ListItem Text="Wallis & Futuna Islands" Value="Wallis & Futuna Islands">  </asp:ListItem>
            <asp:ListItem Text="Yemen" Value="Yemen">  </asp:ListItem>
            <asp:ListItem Text="Zambia" Value="Zambia"> </asp:ListItem>
            <asp:ListItem Text="Zimbabwe" Value="Zimbabwe"> </asp:ListItem>
        </asp:DropDownList>
        <asp:Label ID="lbltime" runat="server" Font-Bold="true" Font-Size="Medium" Font-Names="arial"
            ForeColor="Red"></asp:Label>

 protected void ddlcountry_SelectedIndexChanged(object sender, EventArgs e)
    {
        lbltime.Text=GetCountryTime(ddlcountry.SelectedValue.ToString());

    }
    private string GetCountryTime(string country)
    {
        DateTime gmt = default(DateTime);
        System.DateTime value = default(System.DateTime);
        gmt = DateTime.Now.AddMinutes(-330);

        switch (country)
        {
            case "India":
            case "Sri Lanka":
                return DateTime.Now.ToString();
            case "United Kingdom":
            case "Portugal":
            case "Sierra Leone":
            case "Senegal":
            case "Morocco":
            case "Mali":            
                return gmt.ToString();
            case "France":
            case "Spain":
            case "Slovenia":
            case "Slovakia":
            case "Poland":
            case "Nigeria":
            case "Niger":
            case "Hungary":
            case "Denmark":
            case "Czech Republic":
                return gmt.AddMinutes(60).ToString();
            case "Botswana":
            case "Moldova":
            case "South Africa":
            case "Malawi":
            case "Lithuania":
            case "Libya":
            case "Turkey":
            case "Finland":
            case "Egypt":
                return gmt.AddMinutes(120).ToString(); ;
            case "Bahrain":
            case "Somalia":
            case "Saudi Arabia":
            case "Russia":
            case "Qatar":
            case "Sudan":
            case "Madagascar":
            case "Iraq":
                return gmt.AddMinutes(180).ToString();
            case "Iran":
                return gmt.AddMinutes(220).ToString();
            case "Armenia":
            case "Seychelles":
            case "Reunion":
            case "Oman":
            case "Mauritius":
            case "United Arab Emirates":
            case "Georgia":
            case "Azerbaijan":
                return gmt.AddMinutes(240).ToString();
            case "Afghanistan":
                return gmt.AddMinutes(270).ToString();
            case "Pakistan":
            case "Maldives":
            case "Kyrgyzstan":
                return gmt.AddMinutes(300).ToString();
            case "Nepal":
                return gmt.AddMinutes(345).ToString();
            case "Bangladesh":
            case "Kazakhstan":
                return  gmt.AddMinutes(360).ToString();
            case "Myanmar":
                return  gmt.AddMinutes(390).ToString();                
            case "Cambodia":
            case "Laos":
                return  gmt.AddMinutes(420).ToString();            
            case "Philippines":
            case "Malaysia":
            case "Hong Kong":
            case "China":
                return  gmt.AddMinutes(480).ToString();               
            case "Japan":
            case "Korea":
                return  gmt.AddMinutes(540).ToString();                
            case "Micronesia":
                return  gmt.AddMinutes(720).ToString();               
            case "Papua New Guinea":
            case "Australia":
                return gmt.AddMinutes(600).ToString();
            case "New Caledonia":
                return gmt.AddMinutes(660).ToString();                
            case "New Zealand":
            case "Fiji":
                return  gmt.AddMinutes(720).ToString();
            case "Argentina":
            case "Brazil":
                return  gmt.AddMinutes(-180).ToString();                
            case "Cuba":
                return gmt.AddMinutes(-300).ToString();                    
            case "Aruba":
            case "Paraguay":
            case "Netherlands Antilles":
            case "Barbados":
            case "Chile":
            case "Dominican Republic":
            case "Guyana":
                return gmt.AddMinutes(-240).ToString();
            case "Bahamas":
                return gmt.AddMinutes(-240).ToString();
            case "Peru":
            case "Panama":
            case "Jamaica":
            case "Haiti":
            case "Colombia":
            case "Canary Islands":
                return gmt.AddMinutes(-300).ToString();
            case "Bhutan":
                return gmt.AddMinutes(360).ToString();
            case "Belize":
            case "Mexico":
            case "Honduras":
            case "Canada":
                return gmt.AddMinutes(-360).ToString();
            case "Nicaragua":
                return gmt.AddMinutes(-300).ToString();

            case "United States Of America":
                return gmt.AddMinutes(-480).ToString();
            case "French Polynesia":
                return gmt.AddMinutes(720).ToString();
            case "Samoa":
                return gmt.AddMinutes(-660).ToString();
            case "Singapore":
                return gmt.AddMinutes(480).ToString();
            case "Slovak Republic":
                return gmt.AddMinutes(60).ToString();          
            case "Solomon Islands":
                return gmt.AddMinutes(660).ToString();              
            case "St Helena":
                return gmt.AddMinutes(0).ToString();
            case "St Kitts & Nevia":
                return gmt.AddMinutes(-240).ToString();
            case "St Lucia":
                return gmt.AddMinutes(-240).ToString();           
            case "Surinam":
                return gmt.AddMinutes(-180).ToString();
            case "Swaziland":
                return gmt.AddMinutes(120).ToString();
            case "Sweden":
                return gmt.AddMinutes(60).ToString();
            case "Switzerland":
                return gmt.AddMinutes(60).ToString();
            case "Syria":
                return gmt.AddMinutes(120).ToString();
            case "Taiwan":
                return gmt.AddMinutes(480).ToString();
            case "Tajikistan":
                return gmt.AddMinutes(300).ToString();
            case "Tanzania":
                return gmt.AddMinutes(180).ToString();
            case "Thailand":
                return gmt.AddMinutes(420).ToString();
            case "Tonga":
                return gmt.AddMinutes(0).ToString();
            case "Trinidad & Tobago":
                return gmt.AddMinutes(-240).ToString();
            case "Tunisia":
                return gmt.AddMinutes(60).ToString();          
            case "Turkmenistan":
                return gmt.AddMinutes(300).ToString();
            case "Turks & Caicos Islands":
                return gmt.AddMinutes(-240).ToString();
            case "Tuvalu":
                return gmt.AddMinutes(720).ToString();
            case "Uganda":
                return gmt.AddMinutes(180).ToString();
            case "Ukraine":
                return gmt.AddMinutes(120).ToString();          
            case "Uruguay":
                return gmt.AddMinutes(-180).ToString();
            case "USA":
                return gmt.AddMinutes(-480).ToString();
            case "Uzbekistan":
                return gmt.AddMinutes(300).ToString();
            case "Vanuatu":
                return gmt.AddMinutes(660).ToString();
            case "Venezuela":
                return gmt.AddMinutes(-240).ToString();
            case "Vietnam":
                return gmt.AddMinutes(420).ToString();
            case "Wallis & Futuna Islands":
                return gmt.AddMinutes(720).ToString();
            case "Yemen":
                return gmt.AddMinutes(180).ToString();
            case "Zambia":
                return gmt.AddMinutes(120).ToString();
            case "Zimbabwe":
                return gmt.AddMinutes(120).ToString();
            default:
                return "";
        }
    }