Error in .net calendar control
I have the following code to show event on a calendar

    Private scheduleData As New Dictionary(Of DateTime, String)(5)
    
        Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    
            scheduleData.Add(New DateTime(2011, 1, 9), "Vacation Day")
            scheduleData.Add(New DateTime(2011, 1, 18), "Budget planning meeting")
            scheduleData.Add(New DateTime(2011, 2, 5), "Conference call")
            scheduleData.Add(New DateTime(2011, 2, 10), "Meet with art director")
            scheduleData.Add(New DateTime(2011, 2, 15), "Vacation day")
            'scheduleData.Add(New DateTime(2011, 2, 15), "Go Shopping")
            Calendar1.Caption = "Personal Schedule"
            Calendar1.FirstDayOfWeek = System.Web.UI.WebControls.FirstDayOfWeek.Sunday
            Calendar1.NextPrevFormat = NextPrevFormat.ShortMonth
            Calendar1.TitleFormat = TitleFormat.MonthYear
            Calendar1.ShowGridLines = True
            Calendar1.DayStyle.HorizontalAlign = HorizontalAlign.Left
            Calendar1.DayStyle.VerticalAlign = VerticalAlign.Top
            Calendar1.DayStyle.Height = New Unit(75)
            Calendar1.DayStyle.Width = New Unit(100)
            Calendar1.OtherMonthDayStyle.BackColor = System.Drawing.Color.Cornsilk
            Calendar1.TodaysDate = New DateTime(2011, 1, 1)
            Calendar1.VisibleDate = Calendar1.TodaysDate
        End Sub

And the date render handler

    Protected Sub Calendar1_DayRender(sender As Object, e As System.Web.UI.WebControls.DayRenderEventArgs) Handles Calendar1.DayRender
            If scheduleData.ContainsKey(e.Day.[Date]) Then
                Dim lit As New Literal()
                lit.Text = "<br />"
                e.Cell.Controls.Add(lit)
                Dim lbl As New Label()
                lbl.Text = DirectCast(scheduleData(e.Day.[Date]), String)
                lbl.Font.Size = New FontUnit(FontSize.Small)
                e.Cell.Controls.Add(lbl)
            End If
    
        End Sub



However this work fine if i dont have more than one event in a day but if there are more than one event in a day i get the error below i.e if the line that reads             'scheduleData.Add(New DateTime(2011, 2, 15), "Go Shopping") is uncommented

    An item with the same key has already been added.
    
    Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 
    
    Exception Details: System.ArgumentException: An item with the same key has already been added.


Kindly help me out.
Error in .net calendar control
===

I have the following code to show event on a calendar

    Private scheduleData As New Dictionary(Of DateTime, String)(5)
    
        Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
    
            scheduleData.Add(New DateTime(2011, 1, 9), "Vacation Day")
            scheduleData.Add(New DateTime(2011, 1, 18), "Budget planning meeting")
            scheduleData.Add(New DateTime(2011, 2, 5), "Conference call")
            scheduleData.Add(New DateTime(2011, 2, 10), "Meet with art director")
            scheduleData.Add(New DateTime(2011, 2, 15), "Vacation day")
            'scheduleData.Add(New DateTime(2011, 2, 15), "Go Shopping")
            Calendar1.Caption = "Personal Schedule"
            Calendar1.FirstDayOfWeek = System.Web.UI.WebControls.FirstDayOfWeek.Sunday
            Calendar1.NextPrevFormat = NextPrevFormat.ShortMonth
            Calendar1.TitleFormat = TitleFormat.MonthYear
            Calendar1.ShowGridLines = True
            Calendar1.DayStyle.HorizontalAlign = HorizontalAlign.Left
            Calendar1.DayStyle.VerticalAlign = VerticalAlign.Top
            Calendar1.DayStyle.Height = New Unit(75)
            Calendar1.DayStyle.Width = New Unit(100)
            Calendar1.OtherMonthDayStyle.BackColor = System.Drawing.Color.Cornsilk
            Calendar1.TodaysDate = New DateTime(2011, 1, 1)
            Calendar1.VisibleDate = Calendar1.TodaysDate
        End Sub

And the date render handler

    Protected Sub Calendar1_DayRender(sender As Object, e As System.Web.UI.WebControls.DayRenderEventArgs) Handles Calendar1.DayRender
            If scheduleData.ContainsKey(e.Day.[Date]) Then
                Dim lit As New Literal()
                lit.Text = "<br />"
                e.Cell.Controls.Add(lit)
                Dim lbl As New Label()
                lbl.Text = DirectCast(scheduleData(e.Day.[Date]), String)
                lbl.Font.Size = New FontUnit(FontSize.Small)
                e.Cell.Controls.Add(lbl)
            End If
    
        End Sub



However this work fine if i dont have more than one event in a day but if there are more than one event in a day i get the error below i.e if the line that reads             'scheduleData.Add(New DateTime(2011, 2, 15), "Go Shopping") is uncommented

    An item with the same key has already been added.
    
    Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 
    
    Exception Details: System.ArgumentException: An item with the same key has already been added.


Kindly help me out.