C# Split xml file into multiple files

Question

Below i have an xml file, in this file, i need to split this xml file into multiple xml files based on date column value,
suppose i have 10 records with 3 different dates then all unique date records should go into each file . for ex here i have a file with three dates my output should get 3 files while each file containing all records of unique date data. I didn't get any idea
to proceed on this, thats the reason am not posting any code.Needed urgently please
<XML>
<rootNode>
<childnode>
<date>2012-12-01</date>
<name>SSS</name>
</childnode>
<childnode>
<date>2012-12-01</date>
<name>SSS</name>
</childnode>
<childnode>
<date>2012-12-02</date>
<name>SSS</name>
</childnode>
<childnode>
<date>2012-12-03</date>
<name>SSS</name>
</childnode>
</rootNode>
</XML>

Answer 1

Here is full code:
using System.Xml.Linq;
class curEntity
public DateTime Date;
public string Name;
public curEntity(DateTime _Date, string _Name)
Date = _Date;
Name = _Name;
static void Main(string[] args)
XElement xmlTree = new XElement("XML",
new XElement("rootNode",
new XElement("childnode",
new XElement("date"),
new XElement("name")
string InfilePath = @"C:\temp\1.xml";
string OutFilePath = @"C:\temp\1_";
XDocument xmlDoc = XDocument.Load(InfilePath);
List<curEntity> lst = xmlDoc.Element("XML").Element("rootNode").Elements("childnode")
.Select(element => new curEntity(Convert.ToDateTime(element.Element("date").Value), element.Element("name").Value))
.ToList();
var unique = lst.GroupBy(i => i.Date).Select(i => i.Key);
foreach (DateTime dt in unique)
List<curEntity> CurEntities = lst.FindAll(x => x.Date == dt);
XElement outXML = new XElement("XML",
new XElement("rootNode")
foreach(curEntity ce in CurEntities)
outXML.Element("rootNode").Add(new XElement("childnode",
new XElement("date", ce.Date.ToString("yyyy-MM-dd")),
new XElement("name", ce.Name)
outXML.Save(OutFilePath + dt.ToString("yyyy-MM-dd") + ".xml");
Console.WriteLine("Done");
Console.ReadKey();