About C # getting the dynamic time difference function

In QQ and other space, we often see such a dynamic release and how many seconds ago (32 seconds ago), 1 minutes ago, 1 hours ago, 1 days ago, 1 months ago, but our database in the format of the time to save: 2016-05-18 00:19:21.437-to go to distress and can not be converted, A method is provided below.

/// <summary>        ///         /// </summary>        /// <param name= "DT" >time to publish dynamic</param>        /// <returns></returns>         Public Static stringDatestringfromnow (DateTime DT) {TimeSpan span= DateTime.Now-DT; if(span. Totaldays > -)            {                returndt.            ToShortDateString (); }            Else if(span. Totaldays > -)            {                return "1 months ago"; }            Else if(span. Totaldays > -)            {                return "2 weeks ago"; }            Else if(span. Totaldays >7)            {                return "1 weeks ago"; }            Else if(span. Totaldays >1)            {                return string. Format ("{0} days ago", (int) Math.floor (span.            Totaldays)); }            Else if(span. TotalHours >1)            {                return string. Format ("{0} hours ago", (int) Math.floor (span.            TotalHours)); }            Else if(span. Totalminutes >1)            {                return string. Format ("{0} minutes ago", (int) Math.floor (span.            totalminutes)); }            Else if(span. TotalSeconds >=1)            {                return string. Format ("{0} seconds ago", (int) Math.floor (span.            TotalSeconds)); }            Else            {                return "1 seconds ago"; }         }        #endregion

About C # get dynamic time difference function