日期转时间戳       

        public Int64 ToUnixTimestamp(DateTime date)
        {
            DateTime unixEpoch = new DateTime(1970, 1, 1, 0, 0, 0);
            TimeSpan unixTimeSpan = date - unixEpoch;
            return (Int64)unixTimeSpan.TotalSeconds-28800;
        }

        时间戳转日期

        public DateTime UnixTimestampToDateTime(Int64 unixTime)
        {
            DateTime unixStart = new DateTime(1970, 1, 1, 0, 0, 0, 0, System.DateTimeKind.Utc);
            long unixTimeStampInTicks = (long)(unixTime * TimeSpan.TicksPerSecond);
            return new DateTime(unixStart.Ticks + unixTimeStampInTicks);
        }

日期转时间戳，时间戳转日期