How-to get the current date and the next date in any cultures with C# ?

                    string strGuiDate = "14.03.2008";
                    CultureInfo guiCulture = new CultureInfo("fi-FI");
                    guiCulture.DateTimeFormat.DateSeparator = ".";
                    DateTime datetime = DateTime.Parse(strGuiDate, guiCulture);
                    CultureInfo dbCulture = new CultureInfo("en-US");
                    dbCulture.DateTimeFormat.DateSeparator = "-";

                    string strDbTime = datetime.ToString("yyyy-MM-dd");
                    logger.Debug("strDbTime is " + strDbTime);

                    DateTime datetime1 = datetime.AddDays(1.0);
                    string strDbTime1 = datetime1.ToString("yyyy-MM-dd");
                    logger.Debug("strDbTime1 is " + strDbTime1);