The added or subtracted value results in un-representable Date Time. Parameter name:T
    Dim offset = New Date(1, 1, 1)
    Dim dateOne = dtpbdate.Value
    Dim dateTwo = Date.Now
    Dim diff As TimeSpan = dateTwo - dateOne
    Dim years = (offset + diff).Year - 1
    If years < 18 And years < 50 Then
        MsgBox("Age requirement must be 18 - 50 years old!")
    Else
        txtage.Text = years.ToString
    End If
