時間間隔

<pre name="code" class="csharp"> //獲取本月份天數
                int days = System.Threading.Thread.CurrentThread.CurrentUICulture.Calendar.GetDaysInMonth(dt.Year, dt.Month);
                //15號日期
                DateTime dt15 =Convert.ToDateTime(dt.ToString("MM-15"));
                //月底日期
                DateTime dt30 = Convert.ToDateTime(dt.ToString("MM-"+days+""));
                //第一個返息日
                DateTime dtFirst;

                if (dt > dt15)
                {
                    dtFirst = dt30;
                }
                else
                {
                    dtFirst = dt15;
                }

 /// <summary>
        /// 日期天數差
        /// </summary>
        /// <param name="DateTime1"></param>
        /// <param name="DateTime2"></param>
        /// <returns></returns>
        private int DateDiff(DateTime DateTime1, DateTime DateTime2)
        {
            string dateDiff = null;
            TimeSpan ts1 = new TimeSpan(DateTime1.Ticks);
            TimeSpan ts2 = new TimeSpan(DateTime2.Ticks);
            TimeSpan ts = ts1.Subtract(ts2).Duration();
            dateDiff = ts.Days.ToString(); //+ "天"; +ts.Hours.ToString() + "小時" + ts.Minutes.ToString() + "分鐘" + ts.Seconds.ToString() + "秒";
            return Convert.ToInt32(dateDiff);
        }