The only part of my project that is not working is the DateTimePickerArrival and DateTimePickerDeparture. I'm trying to add a 10% High Season Rate for the months December-February. Right now it is adding the tax to all days. Any help would be appreciated. Thanks!

HTML Code:
Public Sub SetMyCustomFormat()
        ' Set the Format type and the CustomFormat string.
        DateTimePickerArrival.Format = DateTimePickerFormat.Custom
        DateTimePickerArrival.CustomFormat = "MM dd, yyyy"
        DateTimePickerDeparture.Format = DateTimePickerFormat.Custom
        DateTimePickerDeparture.CustomFormat = "MM dd, yyyy"
    End Sub
HTML Code:
 Private Sub AccommodationsTotalButton_Click(sender As System.Object, e As System.EventArgs)Handles AccommodationsTotalButton.Click
        Dim StudioDecimal, OneBedroomDecimal, TwoBedroomDecimal, ThreeBedroomDecimal As Decimal
        Dim DateTimePicker As Date
        
        'Find the price.
        If StudioRadioButton.Checked Then
            StudioDecimal = STUDIO_OFF_Decimal
        ElseIf OneBedroomRadioButton.Checked Then
            OneBedroomDecimal = ONE_BEDROOM_CONDO_OFF_Decimal
        ElseIf TwoBedroomRadioButton.Checked Then
            TwoBedroomDecimal = TWO_BEDROOM_CONDO_OFF_Decimal
        ElseIf ThreeBedroomRadioButton.Checked Then
            ThreeBedroomDecimal = THREE_BEDROOM_CONDO_OFF_Decimal
        ElseIf StudioOnRadioButton.Checked Then
            StudioDecimal = STUDIO_ON_Decimal
        ElseIf OneBedroomOnRadioButton.Checked Then
            OneBedroomDecimal = ONE_BEDROOM_CONDO_ON_Decimal
        ElseIf TwoBedroomOnRadioButton.Checked Then
            TwoBedroomDecimal = TWO_BEDROOM_CONDO_ON_Decimal
        ElseIf ThreeBedroomOnRadioButton.Checked Then
            ThreeBedroomDecimal = THREE_BEDROOM_CONDO_ON_Decimal
        End If
       
        'Display the prices.
        StudioTextBox.Text = CStr(StudioDecimal)
        StudioTextBox.Text = StudioDecimal.ToString("C")
        OneBedroomTextBox.Text = CStr(OneBedroomDecimal)
        OneBedroomTextBox.Text = OneBedroomDecimal.ToString("C")
        TwoBedroomTextBox.Text = CStr(TwoBedroomDecimal)
        TwoBedroomTextBox.Text = TwoBedroomDecimal.ToString("C")
        ThreeBedroomTextBox.Text = CStr(ThreeBedroomDecimal)
        ThreeBedroomTextBox.Text = ThreeBedroomDecimal.ToString("C")

        'Calculate the total Accommodation Price.
        Dim AccommodationDecimal As Decimal = CDec(100.0) ' Amount = 100 $
        Dim HIGH_SEASON_RATE_Decimal As Decimal = CDec(10.0)  ' Rate = 10%
        AccommodationDecimal = StudioDecimal + OneBedroomDecimal + TwoBedroomDecimal + ThreeBedroomDecimal

        'Calculate the total Accommodation Price with High Season.
        If DateTimePicker.Month < 3 OrElse DateTimePicker.Month > 11 Then
            AccommodationDecimal = CDec(AccommodationDecimal + (HIGH_SEASON_RATE_Decimal * 0.01 * AccommodationDecimal))
        End If
        
        AccommodationsTotalTextBox.Text = AccommodationDecimal.ToString("C")
        AccommodationDecimal = CDec(CDec(CDbl(AccommodationsTotalTextBox.Text) * CDbl(VacationDaysTextBox.Text)) * CDbl(NumberPeopleTextBox.Text))
        TotalTextBox.Text = AccommodationDecimal.ToString("C")


    End Sub