Help with Calculating the date

What is the error you are seeing?

Jim

it's hard to say before we see the error, but you can check if your data conversion is happening in the same format all along your code. Like, if I'm using UK date-time format and my project is set to US-English by default, it may be failing to convert something like 31/12/2008.

Cheers,
Yurich

I see several problems in here. Can you tell me what kind of controls are:
txtDateEnd and txtDateStart?

Jim

Try changing the line
txtEndDate = Convert.ToDateTime(txtStartDate).AddDays(14).ToString("d");

to this...
txtEndDate.Text = Convert.ToDateTime(txtStartDate.Text).AddDays(14).ToString("d");

Thanks for all your help. I have another question, If I want to perform the same action in Javascript, can I do Registe.ClientScript.... or do something else. Please Help

Thanks

Hi Jim

I tried your code and getting the following errors:

Error      1      Cannot convert null to 'System.DateTime' because it is a value type
Error      2      Cannot implicitly convert type 'string' to 'System.DateTime'      
Error      3      The name 'txtDateEnd' does not exist in the current context

Any help is appreicated.

My Code:

protected void TextBox_Changed(object sender, EventArgs e)
    {
        int intWeeks = 0;
         
        foreach (DataGridItem item in dgPhaseDisplay.Items)
        {
            TextBox txtWeeks = (TextBox)item.FindControl("txNoWeeks");
            TextBox endDateTB = (TextBox)item.FindControl("txtDateEnd");
            TextBox startDateTB = (TextBox)item.FindControl("txtDateStart");
 
            if (startDateTB == null)
               throw new Exception("Unable to locate startDate textbox.");
 
            if (endDateTB == null)
               throw new Exception("Unable to locate endDate textbox.");
 
            DateTime txtStartDate = DateTime.Parse(startDateTB.Text);
            DateTime endDate = null;
 
            if ((txtWeeks == null) || !int.TryParse(txtWeeks.Text, out intWeeks))
            {
                SetValidationErrorMessage("Please enter the numeric value in the number of weeks.");
            }
            else
            {
                endDate = Convert.ToDateTime(txtStartDate).AddDays(intWeeks * 7).ToString("d");
                txtDateEnd.Text = endDate.ToString();
            }
        }    
    }

--ASP.Net Code:

<asp:datagrid  ID="dgPhaseDisplay" HeaderStyle-Font-Size="x-small" HeaderStyle-Font-Bold="True" HeaderStyle-VerticalAlign="Bottom"
                            AlternatingItemStyle-CssClass="smallcolor1" ItemStyle-VerticalAlign="Top"
                            CellPadding="1" CellSpacing="1" HeaderStyle-BackColor="LightBlue" BorderStyle="None" GridLines="None"
                            PagerStyle-VerticalAlign="Top" AllowSorting="True" AutoGenerateColumns="False" runat="server" ItemStyle-Wrap="True"  >
                            <AlternatingItemStyle CssClass="smallcolor1" ></AlternatingItemStyle>
                            <ItemStyle CssClass="smallcolor2" VerticalAlign="Top" Wrap="True"></ItemStyle>
                            <HeaderStyle Font-Size="X-Small" Font-Bold="True" VerticalAlign="Bottom" BackColor="LightBlue"></HeaderStyle>
                            <Columns>
                                <asp:TemplateColumn HeaderText="Select">
                                    <ItemTemplate>
                                          <asp:CheckBox ID="dgChkBox" runat="server" Checked="false" />
                                 </ItemTemplate>
                            <ItemStyle Width="75px" />
                            <HeaderStyle Width="75px" />
                                  </asp:TemplateColumn>
                                  <asp:BoundColumn DataField="lnkPhaseID" Visible="False" HeaderText="Phase ID" SortExpression="lnkPhaseID"></asp:BoundColumn>
                                  <asp:BoundColumn DataField="lnkPhaseDescp" HeaderText="Phase Descp" SortExpression="lnkPhaseDescp">
                            <ItemStyle Width="250px" />
                            <FooterStyle Font-Size="X-Small" />
                            <HeaderStyle Width="250px" />
                        </asp:BoundColumn>
                                  <asp:TemplateColumn HeaderText="Start Date">
                                        <ItemTemplate>
                                      <peterCC:DateTextBox ID="txtDateStart" runat="server" xEnableContextMenuB="False" Width="75px" >
                                    <xPopupCalendar xToggleImageUrl="PetersDatePackage/Appearance/Calendar.jpg" > </xPopupCalendar>
                            </peterCC:DateTextBox>
                                 </ItemTemplate>
                            <ItemStyle Width="75px" />
                            <HeaderStyle Width="75px" />
                                  </asp:TemplateColumn>
                                  <asp:TemplateColumn HeaderText="# Weeks">
                                        <ItemTemplate>
                                            <asp:TextBox ID="txNoWeeks" runat="server" Text="" Width="30px" MaxLength="4" AutoPostBack="true"
                                            OnTextChanged="TextBox_Changed"  ></asp:TextBox>
                                           </ItemTemplate>
                            <ItemStyle Width="75px" />
                            <HeaderStyle Width="75px" />
                                  </asp:TemplateColumn>
                                  <asp:TemplateColumn HeaderText="End Date">
                                        <ItemTemplate>
                                      <peterCC:DateTextBox ID="txtDateEnd" runat="server" xEnableContextMenuB="False" Width="75px" >
                                    <xPopupCalendar xToggleImageUrl="PetersDatePackage/Appearance/calendar.jpg" > </xPopupCalendar>
                            </peterCC:DateTextBox>
                              </ItemTemplate>
                            <ItemStyle Width="75px" />
                            <HeaderStyle Width="75px" />
                                  </asp:TemplateColumn>
                                  <asp:TemplateColumn HeaderText="Alias Descp">
                                        <ItemTemplate>
                                            <asp:TextBox ID="txtPhaseAlias" runat="server" Text=""></asp:TextBox>
                                           </ItemTemplate>
                            <ItemStyle Width="100px" />
                            <HeaderStyle Width="100px" />
                                  </asp:TemplateColumn>
                            </Columns>
                    <PagerStyle VerticalAlign="Top" />
                      </asp:datagrid>
                   </td>
        </tr>

Jim

I solved the problem.
Thanks for your help. You guys are the best.

Just FYI.. Take a look at the code:

protected void TextBox_Changed(object sender, EventArgs e)
    {
        int intWeeks = 0;
         
        foreach (DataGridItem item in dgPhaseDisplay.Items)
        {
            TextBox txtWeeks = (TextBox)item.FindControl("txNoWeeks");
            TextBox endDateTB = (TextBox)item.FindControl("txtDateEnd");
            TextBox startDateTB = (TextBox)item.FindControl("txtDateStart");
 
            if (startDateTB == null)
               throw new Exception("Unable to locate startDate textbox.");
 
            if (endDateTB == null)
               throw new Exception("Unable to locate endDate textbox.");
           if (startDateTB.Text != "")
           {
               DateTime txtStartDate = DateTime.Parse(startDateTB.Text);
               if ((txtWeeks == null) || !int.TryParse(txtWeeks.Text, out intWeeks))
               {
                   SetValidationErrorMessage("Please enter the numeric value in the number of weeks.");
               }
               else
               {
                   int numberofdays = 0;

                    switch (txtStartDate.DayOfWeek)
                    {
                        case DayOfWeek.Monday:
                        {
                            numberofdays = 3 + (intWeeks * 7);
                            break;
                        }
                        case DayOfWeek.Tuesday:
                        {
                            numberofdays = 3 + (intWeeks * 7);
                            break;
                        }
                        case DayOfWeek.Wednesday:
                        {
                            numberofdays = 3 + (intWeeks * 7);
                            break;
                        }
                        case DayOfWeek.Thursday:
                        {
                            numberofdays = 4 + (intWeeks * 7);
                            break;
                        }
                        case DayOfWeek.Friday:
                        {
                            numberofdays = 3 + (intWeeks * 7);
                            break;
                        }
                        case DayOfWeek.Saturday:
                        {
                            numberofdays = 2 + (intWeeks * 7);
                            break;
                        }
                        case DayOfWeek.Sunday:
                        {
                            numberofdays = 1 + (intWeeks * 7);
                            break;
                        }
                    }
                    string strEndDate = Convert.ToDateTime(txtStartDate).AddDays(numberofdays).ToString("d");
                    endDateTB.Text = strEndDate.ToString();
               }
           }
        }    
    }

show me the lines where you get those errors?

also make sure you do have a textbox named txtDateEnd

Now how can I do the same using Javascript?????

Sorry - I have not used JS in years.

Jim