using System.Globalization;

using System.Reflection;

using System.Xml.Linq;

using System.Xml;

using System.Linq;

using System;

public class Program

{

    public static void Main()

    {

​

        string xmlInput =  @"

    <root>

    <element>

    <timestamp time='2016-09-15T13:45:30'>

    </timestamp>

    </element>

    <element>

    <timestamp time='2016-10-16T13:45:30'>

    </timestamp>

    </element>

    </root>";

        XDocument  xdoc = XDocument.Parse(xmlInput);

​

         xdoc.Descendants("root").Elements("element")

                .Where(x => DateTime.Compare(DateTime.Parse(x.Element("timestamp").Attribute("time").Value,null, DateTimeStyles.RoundtripKind).Date, DateTime.Now.Date) !=0).ToList().ForEach(x => x.Remove());

        Console.WriteLine(xdoc);

​

    }

​

}

​

​