diff --git a/ClosedXML/ClosedXML/ClosedXML.sln b/ClosedXML/ClosedXML/ClosedXML.sln
index 8e08f88..e99f58b 100644
--- a/ClosedXML/ClosedXML/ClosedXML.sln
+++ b/ClosedXML/ClosedXML/ClosedXML.sln
@@ -9,9 +9,11 @@
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ClosedXML_Examples", "ClosedXML_Examples\ClosedXML_Examples.csproj", "{03A518D0-1CB7-488E-861C-C4E782B27A46}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ClosedXML_Net3.5", "ClosedXML_Net3.5\ClosedXML_Net3.5.csproj", "{5F43B12B-A900-40C6-9924-A0C0B032F791}"
+EndProject
 Global
 	GlobalSection(TeamFoundationVersionControl) = preSolution
-		SccNumberOfProjects = 4
+		SccNumberOfProjects = 5
 		SccEnterpriseProvider = {4CA58AB2-18FA-4F8D-95D4-32DDF27D184C}
 		SccTeamFoundationServer = https://tfs.codeplex.com/tfs/tfs09
 		SccLocalPath0 = .
@@ -24,6 +26,9 @@
 		SccProjectUniqueName3 = ClosedXML_Sandbox\\ClosedXML_Sandbox.csproj
 		SccProjectName3 = ClosedXML_Sandbox
 		SccLocalPath3 = ClosedXML_Sandbox
+		SccProjectUniqueName4 = ClosedXML_Net3.5\\ClosedXML_Net3.5.csproj
+		SccProjectName4 = ClosedXML_Net3.5
+		SccLocalPath4 = ClosedXML_Net3.5
 	EndGlobalSection
 	GlobalSection(TestCaseManagementSettings) = postSolution
 		CategoryFile = ClosedXML.vsmdi
@@ -67,6 +72,16 @@
 		{03A518D0-1CB7-488E-861C-C4E782B27A46}.Release|Mixed Platforms.Build.0 = Release|x86
 		{03A518D0-1CB7-488E-861C-C4E782B27A46}.Release|x86.ActiveCfg = Release|x86
 		{03A518D0-1CB7-488E-861C-C4E782B27A46}.Release|x86.Build.0 = Release|x86
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Debug|Mixed Platforms.ActiveCfg = Debug|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Debug|Mixed Platforms.Build.0 = Debug|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Release|Any CPU.Build.0 = Release|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Release|Mixed Platforms.ActiveCfg = Release|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Release|Mixed Platforms.Build.0 = Release|Any CPU
+		{5F43B12B-A900-40C6-9924-A0C0B032F791}.Release|x86.ActiveCfg = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj b/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj
index 09e95a6..ae2ddb4 100644
--- a/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj
+++ b/ClosedXML/ClosedXML/ClosedXML/ClosedXML.csproj
@@ -37,13 +37,13 @@
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="DocumentFormat.OpenXml, Version=2.0.5022.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL" />
+    <Reference Include="Microsoft.CSharp" />
     <Reference Include="System" />
     <Reference Include="System.Core" />
     <Reference Include="System.Drawing" />
     <Reference Include="System.Windows.Forms" />
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
-    <Reference Include="Microsoft.CSharp" />
     <Reference Include="System.Data" />
     <Reference Include="System.Xml" />
     <Reference Include="WindowsBase" />
@@ -128,6 +128,7 @@
   <ItemGroup>
     <WCFMetadata Include="Service References\" />
   </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
index f432c60..52651bd 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/IXLCell.cs
@@ -6,7 +6,7 @@
 
 namespace ClosedXML.Excel
 {
-    public enum XLCellValues { Text, Number, Boolean, DateTime }
+    public enum XLCellValues { Text, Number, Boolean, DateTime, TimeSpan }
 
     public interface IXLCell: IXLStylized
     {
@@ -19,9 +19,11 @@
         Double GetDouble();
         Boolean GetBoolean();
         DateTime GetDateTime();
+        TimeSpan GetTimeSpan();
         void Clear();
         void Delete(XLShiftDeletedCells shiftDeleteCells);
         String FormulaA1 { get; set; }
         String FormulaR1C1 { get; set; }
+        IXLRange AsRange();
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
index aed5052..d1900d0 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
@@ -26,10 +26,19 @@
         {
             get { return cellValue; }
         }
-
+        public IXLRange AsRange()
+        {
+            return worksheet.Range(Address, Address);
+        }
         public T GetValue<T>() 
         {
-            return (T)Convert.ChangeType(Value, typeof(T));
+            if (Value is TimeSpan)
+                if (typeof(T) == typeof(String))
+                    return (T)Convert.ChangeType(Value.ToString(), typeof(T));
+                else
+                    return (T)Value;
+            else
+                return (T)Convert.ChangeType(Value, typeof(T));
         }
         public String GetString()
         {
@@ -57,18 +66,14 @@
             {
                 return (cellValue != "0").ToString();
             }
+            else if (dataType == XLCellValues.TimeSpan)
+            {
+                return cellValue;
+            }
             else if (dataType == XLCellValues.DateTime || IsDateFormat())
             {
-                TimeSpan timeSpan;
-                if (TimeSpan.TryParse(cellValue, out timeSpan))
-                {
-                    return timeSpan.ToString();
-                }
-                else
-                {
-                    String format = GetFormat();
-                    return DateTime.FromOADate(Double.Parse(cellValue)).ToString(format);
-                }
+                String format = GetFormat();
+                return DateTime.FromOADate(Double.Parse(cellValue)).ToString(format);
             }
             else if (dataType == XLCellValues.Number)
             {
@@ -84,7 +89,7 @@
         private bool IsDateFormat()
         {
             return (dataType == XLCellValues.Number 
-                && String.IsNullOrWhiteSpace(Style.NumberFormat.Format)
+                && StringExtensions.IsNullOrWhiteSpace(Style.NumberFormat.Format)
                 && ((Style.NumberFormat.NumberFormatId >= 14
                     && Style.NumberFormat.NumberFormatId <= 22)
                 || (Style.NumberFormat.NumberFormatId >= 45
@@ -94,7 +99,7 @@
         private String GetFormat()
         {
             String format;
-            if (String.IsNullOrWhiteSpace(Style.NumberFormat.Format))
+            if (StringExtensions.IsNullOrWhiteSpace(Style.NumberFormat.Format))
             {
                 var formatCodes = GetFormatCodes();
                 format = formatCodes[Style.NumberFormat.NumberFormatId];
@@ -106,14 +111,13 @@
             return format;
         }
 
-        private Boolean initialized = false;
         private String cellValue = String.Empty;
         public Object Value
         {
             get
             {
                 var fA1 = FormulaA1;
-                if (!String.IsNullOrWhiteSpace(fA1))
+                if (!StringExtensions.IsNullOrWhiteSpace(fA1))
                     return fA1;
 
                 if (dataType == XLCellValues.Boolean)
@@ -128,6 +132,11 @@
                 {
                     return Double.Parse(cellValue);
                 }
+                else if (dataType == XLCellValues.TimeSpan)
+                {
+                    //return (DateTime.FromOADate(Double.Parse(cellValue)) - baseDate);
+                    return TimeSpan.Parse(cellValue);
+                }
                 else
                 {
                     return cellValue;
@@ -215,8 +224,8 @@
                     }
                     else if (m.GetType().IsArray)
                     {
-                        dynamic arr = m;
-                        foreach (var item in arr)
+                        //dynamic arr = m;
+                        foreach (var item in (Array)m)
                         {
                             SetValue(item, ro, co);
                             co++;
@@ -297,90 +306,49 @@
             Double dTest;
             DateTime dtTest;
             Boolean bTest;
-            if (initialized)
+            TimeSpan tsTest;
+            if (val.Length > 0 && val.Substring(0, 1) == "'")
             {
-                if (dataType == XLCellValues.Boolean)
-                {
-                    if (Boolean.TryParse(val, out bTest))
-                        val = bTest ? "1" : "0";
-                    else if (!(val == "1" || val == "0"))
-                        throw new ArgumentException("'" + val + "' is not a Boolean type.");
-                }
-                else if (dataType == XLCellValues.DateTime)
-                {
-                    if (DateTime.TryParse(val, out dtTest))
-                    {
-                        val = dtTest.ToOADate().ToString();
-                    }
-                    else if (!Double.TryParse(val, out dTest))
-                    {
-                        throw new ArgumentException("'" + val + "' is not a DateTime type.");
-                    }
+                val = val.Substring(1, val.Length - 1);
+                dataType = XLCellValues.Text;
+            }
+            else if (value is TimeSpan || (TimeSpan.TryParse(val, out tsTest) && !Double.TryParse(val, out dTest)))
+            {
+                //if (TimeSpan.TryParse(val, out tsTest))
+                //    val = baseDate.Add(tsTest).ToOADate().ToString();
+                //else
+                //{
+                //    TimeSpan timeSpan = (TimeSpan)value;
+                //    val = baseDate.Add(timeSpan).ToOADate().ToString();
+                //}
+                dataType = XLCellValues.TimeSpan;
+                Style.NumberFormat.NumberFormatId = 46;
+            }
+            else if (Double.TryParse(val, out dTest))
+            {
+                dataType = XLCellValues.Number;
+            }
+            else if (DateTime.TryParse(val, out dtTest))
+            {
+                dataType = XLCellValues.DateTime;
 
-                    if (Style.NumberFormat.Format == String.Empty && Style.NumberFormat.NumberFormatId == 0)
-                    {
-                        if (dtTest.Date == dtTest)
-                            Style.NumberFormat.NumberFormatId = 14;
-                        else
-                            Style.NumberFormat.NumberFormatId = 22;
-                    }
+                if (dtTest.Date == dtTest)
+                    Style.NumberFormat.NumberFormatId = 14;
+                else
+                    Style.NumberFormat.NumberFormatId = 22;
 
-                }
-                else if (dataType == XLCellValues.Number)
-                {
-                    if (value is TimeSpan)
-                    {
-                        var timeSpan = (TimeSpan)value;
-                        val = baseDate.Add(timeSpan).ToOADate().ToString();
-                        if (Style.NumberFormat.Format == String.Empty && Style.NumberFormat.NumberFormatId == 0)
-                            Style.NumberFormat.NumberFormatId = 46;
-                    }
-                    else
-                    {
-                        if (!Double.TryParse(val, out dTest))
-                            throw new ArgumentException("'" + val + "' is not a Numeric type.");
-                    }
-                }
+                val = dtTest.ToOADate().ToString();
+            }
+            else if (Boolean.TryParse(val, out bTest))
+            {
+                dataType = XLCellValues.Boolean;
+                val = bTest ? "1" : "0";
             }
             else
             {
-                if (val.Length > 0 && val.Substring(0, 1) == "'")
-                {
-                    val = val.Substring(1, val.Length - 1);
-                    dataType = XLCellValues.Text;
-                }
-                else if (value is TimeSpan)
-                {
-                    var timeSpan = (TimeSpan)value;
-                    val = baseDate.Add(timeSpan).ToOADate().ToString();
-                    dataType = XLCellValues.Number;
-                    Style.NumberFormat.NumberFormatId = 46;
-                }
-                else if (Double.TryParse(val, out dTest))
-                {
-                    dataType = XLCellValues.Number;
-                }
-                else if (DateTime.TryParse(val, out dtTest))
-                {
-                    dataType = XLCellValues.DateTime;
-
-                    if (dtTest.Date == dtTest)
-                        Style.NumberFormat.NumberFormatId = 14;
-                    else
-                        Style.NumberFormat.NumberFormatId = 22;
-
-                    val = dtTest.ToOADate().ToString();
-                }
-                else if (Boolean.TryParse(val, out bTest))
-                {
-                    dataType = XLCellValues.Boolean;
-                    val = bTest ? "1" : "0";
-                }
-                else
-                {
-                    dataType = XLCellValues.Text;
-                }
+                dataType = XLCellValues.Text;
             }
+
             cellValue = val;
         }
 
@@ -422,22 +390,22 @@
             }
             set
             {
-                initialized = true;
-                if (cellValue.Length > 0)
+                if (dataType != value)
                 {
-                    TimeSpan tsTest;
-                    if (value == XLCellValues.Boolean)
+                    if (cellValue.Length > 0)
                     {
-                        Boolean bTest;
-                        if (Boolean.TryParse(cellValue, out bTest))
-                            cellValue = bTest ? "1" : "0";
-                        else
-                            cellValue = cellValue == "0" || String.IsNullOrEmpty(cellValue) ? "0" : "1";
-                    }
-                    else if (value == XLCellValues.DateTime && !TimeSpan.TryParse(cellValue, out tsTest))
-                    {
-                        DateTime dtTest;
-                        Double dblTest;
+                        if (value == XLCellValues.Boolean)
+                        {
+                            Boolean bTest;
+                            if (Boolean.TryParse(cellValue, out bTest))
+                                cellValue = bTest ? "1" : "0";
+                            else
+                                cellValue = cellValue == "0" || String.IsNullOrEmpty(cellValue) ? "0" : "1";
+                        }
+                        else if (value == XLCellValues.DateTime)
+                        {
+                            DateTime dtTest;
+                            Double dblTest;
                             if (DateTime.TryParse(cellValue, out dtTest))
                             {
                                 cellValue = dtTest.ToOADate().ToString();
@@ -456,34 +424,52 @@
                                     Style.NumberFormat.NumberFormatId = 14;
                                 else
                                     Style.NumberFormat.NumberFormatId = 22;
-                    }
-                    else if (value == XLCellValues.Number)
-                    {
-                        if (TimeSpan.TryParse(cellValue, out tsTest))
+                        }
+                        else if (value == XLCellValues.TimeSpan)
                         {
-                            cellValue = baseDate.Add(tsTest).ToOADate().ToString();
-                            if (Style.NumberFormat.Format == String.Empty && Style.NumberFormat.NumberFormatId == 0)
-                                Style.NumberFormat.NumberFormatId = 46;
+                            TimeSpan tsTest;
+                            if (TimeSpan.TryParse(cellValue, out tsTest))
+                            {
+                                cellValue = tsTest.ToString();
+                                if (Style.NumberFormat.Format == String.Empty && Style.NumberFormat.NumberFormatId == 0)
+                                    Style.NumberFormat.NumberFormatId = 46;
+                            }
+                            else
+                            {
+                                try
+                                {
+                                    cellValue = (DateTime.FromOADate(Double.Parse(cellValue)) - baseDate).ToString();
+                                }
+                                catch
+                                {
+                                    throw new ArgumentException("Cannot set data type to TimeSpan because '" + cellValue + "' is not recognized as a TimeSpan.");
+                                }
+                            }
+                        }
+                        else if (value == XLCellValues.Number)
+                        {
+                            Double dTest;
+                            if (Double.TryParse(cellValue, out dTest))
+                            {
+                                cellValue = Double.Parse(cellValue).ToString();
+                            }
+                            else
+                            {
+                                throw new ArgumentException("Cannot set data type to Number because '" + cellValue + "' is not recognized as a number.");
+                            }
                         }
                         else
                         {
-                            cellValue = Double.Parse(cellValue).ToString();
-                        }
-                    }
-                    else
-                    {
-                        var formatCodes = GetFormatCodes();
-                        if (dataType == XLCellValues.Boolean)
-                        {
-                            cellValue = (cellValue != "0").ToString();
-                        }
-                        else if (dataType == XLCellValues.Number)
-                        {
-                            if (Style.NumberFormat.NumberFormatId == 46)
+                            var formatCodes = GetFormatCodes();
+                            if (dataType == XLCellValues.Boolean)
                             {
-                                cellValue = (DateTime.FromOADate(Double.Parse(cellValue)) - baseDate).ToString();
+                                cellValue = (cellValue != "0").ToString();
                             }
-                            else
+                            else if (dataType == XLCellValues.TimeSpan)
+                            {
+                                cellValue = TimeSpan.Parse(cellValue).ToString();
+                            }
+                            else if (dataType == XLCellValues.Number)
                             {
                                 String format;
                                 if (Style.NumberFormat.NumberFormatId > 0)
@@ -492,19 +478,19 @@
                                     format = Style.NumberFormat.Format;
                                 cellValue = Double.Parse(cellValue).ToString(format);
                             }
-                        }
-                        else if (dataType == XLCellValues.DateTime)
-                        {
-                            String format;
-                            if (Style.NumberFormat.NumberFormatId > 0)
-                                format = formatCodes[Style.NumberFormat.NumberFormatId];
-                            else
-                                format = Style.NumberFormat.Format;
-                            cellValue = DateTime.FromOADate(Double.Parse(cellValue)).ToString(format);
+                            else if (dataType == XLCellValues.DateTime)
+                            {
+                                String format;
+                                if (Style.NumberFormat.NumberFormatId > 0)
+                                    format = formatCodes[Style.NumberFormat.NumberFormatId];
+                                else
+                                    format = Style.NumberFormat.Format;
+                                cellValue = DateTime.FromOADate(Double.Parse(cellValue)).ToString(format);
+                            }
                         }
                     }
+                    dataType = value;
                 }
-                dataType = value;
             }
         }
 
@@ -572,7 +558,7 @@
         {
             get 
             {
-                if (String.IsNullOrWhiteSpace(formulaR1C1))
+                if (StringExtensions.IsNullOrWhiteSpace(formulaR1C1))
                     formulaR1C1 = GetFormulaR1C1(FormulaA1);
 
                 return formulaR1C1; 
@@ -606,7 +592,7 @@
             + @"|(?<=\W)([Cc]\[?-?\d{0,5}\]?:[Cc]\[?-?\d{0,5}\]?)(?=\W)"); // C:C
         private String GetFormula(String strValue, FormulaConversionType conversionType)
         {
-            if (String.IsNullOrWhiteSpace(strValue))
+            if (StringExtensions.IsNullOrWhiteSpace(strValue))
                 return String.Empty;
 
             var value = ">" + strValue + "<";
@@ -672,22 +658,6 @@
 
                 var columnPart = addressToUse.Substring(addressToUse.IndexOf("C"));
                 String columnToReturn = GetA1Column(columnPart);
-                //var cIndex = addressToUse.IndexOf("C");
-                //String columnToReturn;
-                //if (cIndex == addressToUse.Length - 1)
-                //{
-                //    columnToReturn = Address.ColumnLetter;
-                //}
-                //else
-                //{
-                //    var columnPart = addressToUse.Substring(cIndex);
-                //    var bIndex = columnPart.IndexOf("[");
-                //    if (bIndex >= 0)
-                //        columnToReturn = XLAddress.GetColumnLetterFromNumber(
-                //            Address.ColumnNumber + Int32.Parse(columnPart.Substring(bIndex + 1, columnPart.Length - bIndex - 2)));
-                //    else
-                //        columnToReturn = "$" + XLAddress.GetColumnLetterFromNumber(Int32.Parse(columnPart.Substring(1)));
-                //}
 
                 var retAddress = columnToReturn + rowToReturn;
                 return retAddress;
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs
index f2c0e44..0d966f3 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Columns/XLColumns.cs
@@ -19,7 +19,9 @@
         List<XLColumn> columns = new List<XLColumn>();
         public IEnumerator<IXLColumn> GetEnumerator()
         {
-            return columns.ToList<IXLColumn>().GetEnumerator();
+            var retList = new List<IXLColumn>();
+            columns.ForEach(c => retList.Add(c));
+            return retList.GetEnumerator();
         }
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs
index b92ca17..94e1349 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRange.cs
@@ -11,5 +11,13 @@
         IXLRanges Ranges { get; }
         IXLRange Range { get; }
         String Comment { get; set; }
+        IXLRanges Add(String rangeAddress);
+        IXLRanges Add(IXLRange range);
+        IXLRanges Add(IXLRanges ranges);
+        void Delete();
+        void Clear();
+        void Remove(String rangeAddress);
+        void Remove(IXLRange range);
+        void Remove(IXLRanges ranges);
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs
index 221d369..c081849 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/IXLNamedRanges.cs
@@ -14,5 +14,6 @@
         IXLNamedRange Add(String rangeName, IXLRanges ranges, String comment = null);
         void Delete(String rangeName);
         void Delete(Int32 rangeIndex);
+        void DeleteAll();
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
index c6b9e40..481c828 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRange.cs
@@ -8,21 +8,21 @@
     internal class XLNamedRange: IXLNamedRange
     {
         private List<String> rangeList = new List<String>();
-        private XLWorkbook workbook;
-        public XLNamedRange(XLWorkbook workbook, String rangeName, String range, String comment = null)
+        private XLNamedRanges namedRanges;
+        public XLNamedRange(XLNamedRanges namedRanges , String rangeName, String range,  String comment = null)
         {
             Name = rangeName;
             rangeList.Add(range);
             Comment = comment;
-            this.workbook = workbook;
+            this.namedRanges = namedRanges;
         }
 
-        public XLNamedRange(XLWorkbook workbook, String rangeName, IXLRanges ranges, String comment = null)
+        public XLNamedRange(XLNamedRanges namedRanges, String rangeName, IXLRanges ranges, String comment = null)
         {
             Name = rangeName;
             ranges.ForEach(r => rangeList.Add(r.ToString()));
             Comment = comment;
-            this.workbook = workbook;
+            this.namedRanges = namedRanges;
         }
 
         public String Name { get; set; }
@@ -30,13 +30,13 @@
         {
             get
             {
-                var ranges = new XLRanges(workbook.Style);
+                var ranges = new XLRanges(namedRanges.Workbook, namedRanges.Workbook.Style);
                 foreach (var rangeAddress in rangeList)
                 {
                     var byExclamation = rangeAddress.Split('!');
                     var wsName = byExclamation[0].Replace("'", "");
                     var rng = byExclamation[1];
-                    var rangeToAdd = workbook.Worksheets.Worksheet(wsName).Range(rng);
+                    var rangeToAdd = namedRanges.Workbook.Worksheets.Worksheet(wsName).Range(rng);
                     ranges.Add(rangeToAdd);
                 }
                 return ranges;
@@ -51,6 +51,46 @@
         }
         public String Comment { get; set; }
 
+        public IXLRanges Add(String rangeAddress)
+        {
+            var ranges = new XLRanges(namedRanges.Workbook, namedRanges.Workbook.Style);
+            ranges.Add(rangeAddress);
+            return Add(ranges);
+        }
+        public IXLRanges Add(IXLRange range)
+        {
+            var ranges = new XLRanges(((XLRange)range).Worksheet.Internals.Workbook, range.Style);
+            ranges.Add(range);
+            return Add(ranges);
+        }
+        public IXLRanges Add(IXLRanges ranges)
+        {
+            ranges.ForEach(r => rangeList.Add(r.ToString()));
+            return ranges;
+        }
+
+        public void Delete()
+        {
+            namedRanges.Delete(Name);
+        }
+        public void Clear()
+        {
+            rangeList.Clear();
+        }
+        public void Remove(String rangeAddress)
+        {
+            rangeList.Remove(rangeAddress);
+        }
+        public void Remove(IXLRange range)
+        {
+            rangeList.Remove(range.ToString());
+        }
+        public void Remove(IXLRanges ranges)
+        {
+            ranges.ForEach(r => rangeList.Remove(r.ToString()));
+        }
+
+
         public override string ToString()
         {
             String retVal = rangeList.Aggregate(String.Empty, (agg, r) => agg += r + ",");
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
index 5e82a1e..2e49830 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/NamedRanges/XLNamedRanges.cs
@@ -8,10 +8,11 @@
     internal class XLNamedRanges: IXLNamedRanges
     {
         Dictionary<String, IXLNamedRange> namedRanges = new Dictionary<String, IXLNamedRange>();
-        private XLWorkbook workbook;
+        internal XLWorkbook Workbook { get; set; }
+       
         public XLNamedRanges(XLWorkbook workbook)
         {
-            this.workbook = workbook;
+            this.Workbook = workbook;
         }
 
         #region IXLNamedRanges Members
@@ -28,21 +29,21 @@
 
         public IXLNamedRange Add(String rangeName, String rangeAddress, String comment = null)
         {
-            var namedRange = new XLNamedRange(workbook, rangeName, rangeAddress, comment);
+            var namedRange = new XLNamedRange(this, rangeName, rangeAddress, comment);
             namedRanges.Add(rangeName, namedRange);
             return namedRange;
         }
 
         public IXLNamedRange Add(String rangeName, IXLRange range, String comment = null)
         {
-            var ranges = new XLRanges(range.Style);
+            var ranges = new XLRanges(((XLRange)range).Worksheet.Internals.Workbook, range.Style);
             ranges.Add(range);
             return Add(rangeName, ranges, comment);
         }
 
         public IXLNamedRange Add(String rangeName, IXLRanges ranges, String comment = null)
         {
-            var namedRange = new XLNamedRange(workbook, rangeName, ranges, comment);
+            var namedRange = new XLNamedRange(this, rangeName, ranges, comment);
             namedRanges.Add(rangeName, namedRange);
             return namedRange;
         }
@@ -51,11 +52,14 @@
         {
             namedRanges.Remove(rangeName);
         }
-
         public void Delete(Int32 rangeIndex)
         {
             namedRanges.Remove(namedRanges.ElementAt(rangeIndex).Key);
         }
+        public void DeleteAll()
+        {
+            namedRanges.Clear();
+        }
         
         #endregion
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs
index e5ac900..0a2de52 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/IXLRangeBase.cs
@@ -21,10 +21,10 @@
         IXLRange Range(IXLAddress firstCellAddress, IXLAddress lastCellAddress);
         IXLRanges Ranges(params string[] ranges);
         IXLRanges Ranges(string ranges);
-        void Unmerge();
-        void Merge();
+        IXLRange Unmerge();
+        IXLRange Merge();
         IXLRange AsRange();
         Boolean ContainsRange(String rangeAddress);
-        void CreateNamedRange(String rangeName, XLScope scope = XLScope.Workbook, String comment = null);
+        IXLRange AddToNamed(String rangeName, XLScope scope = XLScope.Workbook, String comment = null);
     }
 }
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
index 5f35186..8a6fcb9 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeBase.cs
@@ -5,7 +5,7 @@
 
 namespace ClosedXML.Excel
 {
-    internal abstract class XLRangeBase: IXLRangeBase
+    internal abstract class XLRangeBase : IXLRangeBase
     {
         public XLRangeBase(IXLRangeAddress rangeAddress)
         {
@@ -166,7 +166,7 @@
 
         public IXLRanges Ranges( String ranges)
         {
-            var retVal = new XLRanges(Worksheet.Style);
+            var retVal = new XLRanges(Worksheet.Internals.Workbook, Worksheet.Style);
             var rangePairs = ranges.Split(',');
             foreach (var pair in rangePairs)
             {
@@ -176,7 +176,7 @@
         }
         public IXLRanges Ranges( params String[] ranges)
         {
-            var retVal = new XLRanges(Worksheet.Style);
+            var retVal = new XLRanges(Worksheet.Internals.Workbook, Worksheet.Style);
             foreach (var pair in ranges)
             {
                 retVal.Add(this.Range(pair));
@@ -196,18 +196,25 @@
         }
         public IEnumerable<IXLCell> CellsUsed()
         {
-            return this.Worksheet.Internals.CellsCollection.Where(c => this.ContainsRange(c.Key.ToString())).Select(c => c.Value).AsEnumerable<IXLCell>();
+            var list = this.Worksheet.Internals.CellsCollection.Where(c => this.ContainsRange(c.Key.ToString())).Select(c => c.Value);
+            var retList = new List<IXLCell>();
+            list.ForEach(c => retList.Add(c));
+            return retList.AsEnumerable();
         }
 
-        public void Merge()
+        public IXLRange Merge()
         {
             var mergeRange = this.RangeAddress.FirstAddress.ToString() + ":" + this.RangeAddress.LastAddress.ToString();
             if (!this.Worksheet.Internals.MergedCells.Contains(mergeRange))
                 this.Worksheet.Internals.MergedCells.Add(mergeRange);
+            return AsRange();
         }
-        public void Unmerge()
+        public IXLRange Unmerge()
         {
-            this.Worksheet.Internals.MergedCells.Remove(this.RangeAddress.FirstAddress.ToString() + ":" + this.RangeAddress.LastAddress.ToString());
+            var mergeRange = this.RangeAddress.FirstAddress.ToString() + ":" + this.RangeAddress.LastAddress.ToString();
+            if (this.Worksheet.Internals.MergedCells.Contains(mergeRange))
+            this.Worksheet.Internals.MergedCells.Remove(mergeRange);
+            return AsRange();
         }
 
 
@@ -581,16 +588,28 @@
             }
         }
 
-        public void CreateNamedRange(String rangeName, XLScope scope = XLScope.Workbook, String comment = null)
+        public IXLRange AddToNamed(String rangeName, XLScope scope = XLScope.Workbook, String comment = null)
         {
+            IXLNamedRanges namedRanges;
             if (scope == XLScope.Workbook)
             {
-                Worksheet.Internals.Workbook.NamedRanges.Add(rangeName, this.AsRange(), comment);
+                namedRanges = Worksheet.Internals.Workbook.NamedRanges;
             }
             else
             {
-                Worksheet.NamedRanges.Add(rangeName, this.AsRange(), comment);
+                namedRanges = Worksheet.NamedRanges;
             }
+
+            if (namedRanges.Where(nr => nr.Name.ToLower() == rangeName.ToLower()).Any())
+            {
+                var namedRange = namedRanges.Where(nr => nr.Name.ToLower() == rangeName.ToLower()).Single();
+                namedRange.Add(this.AsRange());
+            }
+            else
+            {
+                namedRanges.Add(rangeName, this.AsRange(), comment);
+            }
+            return AsRange();
         }
 
         protected void ShiftColumns(IXLRangeAddress thisRangeAddress, XLRange shiftedRange, int columnsShifted)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumns.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumns.cs
index 40a6b76..2f17867 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumns.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeColumns.cs
@@ -26,7 +26,9 @@
 
         public IEnumerator<IXLRangeColumn> GetEnumerator()
         {
-            return ranges.ToList<IXLRangeColumn>().GetEnumerator();
+            var retList = new List<IXLRangeColumn>();
+            ranges.ForEach(c => retList.Add(c));
+            return retList.GetEnumerator();
         }
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRows.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRows.cs
index ce0d6e4..ec1f47a 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRows.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRangeRows.cs
@@ -26,7 +26,9 @@
 
         public IEnumerator<IXLRangeRow> GetEnumerator()
         {
-            return ranges.ToList<IXLRangeRow>().GetEnumerator();
+            var retList = new List<IXLRangeRow>();
+            ranges.ForEach(c => retList.Add(c));
+            return retList.GetEnumerator();
         }
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRanges.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRanges.cs
index 4cd6cc2..75ecc26 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRanges.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Ranges/XLRanges.cs
@@ -7,8 +7,10 @@
 {
     internal class XLRanges : IXLRanges
     {
-        public XLRanges(IXLStyle defaultStyle)
+        private XLWorkbook workbook;
+        public XLRanges(XLWorkbook workbook, IXLStyle defaultStyle)
         {
+            this.workbook = workbook;
             Style = defaultStyle;
         }
 
@@ -23,7 +25,14 @@
         {
             ranges.Add((XLRange)range);
         }
-
+        public void Add(String rangeAddress)
+        {
+            var byExclamation = rangeAddress.Split('!');
+            var wsName = byExclamation[0].Replace("'", "");
+            var rng = byExclamation[1];
+            var rangeToAdd = workbook.Worksheets.Worksheet(wsName).Range(rng);
+            ranges.Add((XLRange)rangeToAdd);
+        }
         public void Remove(IXLRange range)
         {
             ranges.RemoveAll(r => r.ToString() == range.ToString());
@@ -31,7 +40,9 @@
 
         public IEnumerator<IXLRange> GetEnumerator()
         {
-            return ranges.ToList<IXLRange>().GetEnumerator();
+            var retList = new List<IXLRange>();
+            ranges.ForEach(c => retList.Add(c));
+            return retList.GetEnumerator();
         }
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
@@ -51,7 +62,10 @@
             set
             {
                 style = new XLStyle(this, value);
-
+                foreach (var rng in ranges)
+                {
+                    rng.Style = value;
+                }
             }
         }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs
index b46050d..23ec0c3 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Rows/XLRows.cs
@@ -20,7 +20,9 @@
 
         public IEnumerator<IXLRow> GetEnumerator()
         {
-            return rows.ToList<IXLRow>().GetEnumerator();
+            var retList = new List<IXLRow>();
+            rows.ForEach(c => retList.Add(c));
+            return retList.GetEnumerator();
         }
 
         System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs
index 681b891..de7dfac 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Style/XLFont.cs
@@ -224,7 +224,7 @@
 
         public Double GetWidth(String text)
         {
-            if (String.IsNullOrWhiteSpace(text))
+            if (StringExtensions.IsNullOrWhiteSpace(text))
                 return 0;
 
             System.Drawing.Font stringFont = new System.Drawing.Font(fontName, (float)fontSize);
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
index c7ceb19..9f57d6d 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -210,10 +210,9 @@
                     {
                         if (dCell.DataType == CellValues.SharedString)
                         {
-                            xlCell.DataType = XLCellValues.Text;
                             if (dCell.CellValue != null)
                             {
-                                if (!String.IsNullOrWhiteSpace(dCell.CellValue.Text))
+                                if (!StringExtensions.IsNullOrWhiteSpace(dCell.CellValue.Text))
                                     xlCell.Value = sharedStrings[Int32.Parse(dCell.CellValue.Text)].InnerText;
                                 else
                                     xlCell.Value = dCell.CellValue.Text;
@@ -222,21 +221,24 @@
                             {
                                 xlCell.Value = String.Empty;
                             }
+                            xlCell.DataType = XLCellValues.Text;
                         }
                         else if (dCell.DataType == CellValues.Date)
                         {
-                            xlCell.DataType = XLCellValues.DateTime;
                             xlCell.Value = DateTime.FromOADate(Double.Parse(dCell.CellValue.Text));
                         }
                         else if (dCell.DataType == CellValues.Boolean)
                         {
-                            xlCell.DataType = XLCellValues.Boolean;
                             xlCell.Value = (dCell.CellValue.Text == "1");
                         }
                         else if (dCell.DataType == CellValues.Number)
                         {
-                            xlCell.DataType = XLCellValues.Number;
                             xlCell.Value = dCell.CellValue.Text;
+                            var numberFormatId = ((CellFormat)((CellFormats)s.CellFormats).ElementAt(styleIndex)).NumberFormatId;
+                            if (numberFormatId == 46U)
+                                xlCell.DataType = XLCellValues.TimeSpan;
+                            else
+                                xlCell.DataType = XLCellValues.Number;
                         }
                     }
                     else if (dCell.CellValue != null)
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
index 1d84f17..72963f0 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -13,7 +13,7 @@
 using System.Text;
 using System.IO;
 using System.Globalization;
-using System.IO.Packaging;
+//using System.IO.Packaging;
 
 
 
@@ -107,6 +107,7 @@
                 case XLCellValues.DateTime: return CellValues.Date;
                 case XLCellValues.Number: return CellValues.Number;
                 case XLCellValues.Text: return CellValues.SharedString;
+                case XLCellValues.TimeSpan: return CellValues.Number;
                 default: throw new NotImplementedException();
             }
         }
@@ -412,7 +413,7 @@
 
             if (Properties.Manager != null)
             {
-                if (!String.IsNullOrWhiteSpace(Properties.Manager))
+                if (!StringExtensions.IsNullOrWhiteSpace(Properties.Manager))
                 {
                     if (properties.Manager == null)
                         properties.Manager = new Ap.Manager();
@@ -427,7 +428,7 @@
 
             if (Properties.Company != null)
             {
-                if (!String.IsNullOrWhiteSpace(Properties.Company))
+                if (!StringExtensions.IsNullOrWhiteSpace(Properties.Company))
                 {
                     if (properties.Company == null)
                         properties.Company = new Ap.Company();
@@ -583,7 +584,7 @@
                         LocalSheetId = sheetId,
                         Text = nr.ToString()
                     };
-                    if (!String.IsNullOrWhiteSpace(nr.Comment)) definedName.Comment = nr.Comment;
+                    if (!StringExtensions.IsNullOrWhiteSpace(nr.Comment)) definedName.Comment = nr.Comment;
                     definedNames.Append(definedName);
                 }
 
@@ -629,7 +630,7 @@
                     Name = nr.Name,
                     Text = nr.ToString()
                 };
-                if (!String.IsNullOrWhiteSpace(nr.Comment)) definedName.Comment = nr.Comment;
+                if (!StringExtensions.IsNullOrWhiteSpace(nr.Comment)) definedName.Comment = nr.Comment;
                 definedNames.Append(definedName);
             }
 
@@ -673,7 +674,7 @@
         private void GenerateSharedStringTablePartContent(SharedStringTablePart sharedStringTablePart)
         {
             List<String> modifiedStrings = new List<String>();
-            Worksheets.Cast<XLWorksheet>().ForEach(w => modifiedStrings.AddRange(w.Internals.CellsCollection.Values.Where(c => c.DataType == XLCellValues.Text && !String.IsNullOrWhiteSpace(c.InnerText)).Select(c => c.GetString()).Distinct()));
+            Worksheets.Cast<XLWorksheet>().ForEach(w => modifiedStrings.AddRange(w.Internals.CellsCollection.Values.Where(c => c.DataType == XLCellValues.Text && !StringExtensions.IsNullOrWhiteSpace(c.InnerText)).Select(c => c.GetString()).Distinct()));
 
             List<String> existingStrings;
             if (sharedStringTablePart.SharedStringTable != null)
@@ -1304,7 +1305,7 @@
         {
             var newXLNumberFormat = new XLNumberFormat();
             
-            if (nf.FormatCode != null && !String.IsNullOrWhiteSpace(nf.FormatCode.Value))
+            if (nf.FormatCode != null && !StringExtensions.IsNullOrWhiteSpace(nf.FormatCode.Value))
                 newXLNumberFormat.Format = nf.FormatCode.Value;
             else if (nf.NumberFormatId != null)
                 newXLNumberFormat.NumberFormatId = (Int32)nf.NumberFormatId.Value;
@@ -1406,7 +1407,7 @@
 
             #region Columns
             Columns columns = null;
-            if (xlWorksheet.Internals.CellsCollection.Count == 0)
+            if (xlWorksheet.Internals.CellsCollection.Count == 0 && xlWorksheet.Internals.ColumnsCollection.Count == 0)
             {
                 worksheetPart.Worksheet.RemoveAllChildren<Columns>();
             }
@@ -1619,7 +1620,7 @@
                     }
 
                     cell.StyleIndex = styleId;
-                    if (!String.IsNullOrWhiteSpace(opCell.Value.FormulaA1))
+                    if (!StringExtensions.IsNullOrWhiteSpace(opCell.Value.FormulaA1))
                     {
                         cell.CellFormula = new CellFormula(opCell.Value.FormulaA1);
                         cell.CellValue = null;
@@ -1634,7 +1635,7 @@
                         CellValue cellValue = new CellValue();
                         if (dataType == XLCellValues.Text)
                         {
-                            if (String.IsNullOrWhiteSpace(opCell.Value.InnerText))
+                            if (StringExtensions.IsNullOrWhiteSpace(opCell.Value.InnerText))
                             {
                                 if (isNewCell)
                                     cellValue = null;
@@ -1647,17 +1648,15 @@
                             }
                             cell.CellValue = cellValue;
                         }
+                        else if (dataType == XLCellValues.TimeSpan)
+                        {
+                            TimeSpan timeSpan = opCell.Value.GetTimeSpan();
+                            cellValue.Text = XLCell.baseDate.Add(timeSpan).ToOADate().ToString(CultureInfo.InvariantCulture);
+                            cell.CellValue = cellValue;
+                        }
                         else if (dataType == XLCellValues.DateTime || dataType == XLCellValues.Number)
                         {
-                            TimeSpan timeSpan;
-                            if (TimeSpan.TryParse(opCell.Value.InnerText, out timeSpan))
-                            {
-                                cellValue.Text = XLCell.baseDate.Add(timeSpan).ToOADate().ToString(CultureInfo.InvariantCulture);
-                            }
-                            else
-                            {
-                                cellValue.Text = Double.Parse(opCell.Value.InnerText).ToString(CultureInfo.InvariantCulture);
-                            }
+                            cellValue.Text = Double.Parse(opCell.Value.InnerText).ToString(CultureInfo.InvariantCulture);
                             cell.CellValue = cellValue;
                         }
                         else
@@ -1999,7 +1998,7 @@
             CalculationChain calculationChain =  workbookPart.CalculationChainPart.CalculationChain;
             foreach (var worksheet in Worksheets.Cast<XLWorksheet>())
             {
-                foreach (var c in worksheet.Internals.CellsCollection.Values.Where(c => !String.IsNullOrWhiteSpace(c.FormulaA1)))
+                foreach (var c in worksheet.Internals.CellsCollection.Values.Where(c => !StringExtensions.IsNullOrWhiteSpace(c.FormulaA1)))
                 {
                     var calculationCells = calculationChain.Elements<CalculationCell>().Where(
                         cc => cc.CellReference != null && cc.CellReference == c.Address.ToString()).Select(cc=>cc);
@@ -2029,7 +2028,7 @@
                         .Where(c1 => c1.SheetId != null)
                         .Select(c1 => c1.CellReference.Value)
                         .Contains(cc.CellReference.Value)
-                        || worksheet.Internals.CellsCollection.Where(kp=>kp.Key.ToString() == cc.CellReference.Value && String.IsNullOrWhiteSpace(kp.Value.FormulaA1)).Any()
+                        || worksheet.Internals.CellsCollection.Where(kp=>kp.Key.ToString() == cc.CellReference.Value && StringExtensions.IsNullOrWhiteSpace(kp.Value.FormulaA1)).Any()
                     select cc;
             m.ForEach(cc => cCellsToRemove.Add(cc));
             cCellsToRemove.ForEach(cc=>calculationChain.RemoveChild(cc));
diff --git a/ClosedXML/ClosedXML/ClosedXML/Extensions.cs b/ClosedXML/ClosedXML/ClosedXML/Extensions.cs
index 1d11c76..c92bb4c 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Extensions.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Extensions.cs
@@ -79,5 +79,23 @@
             }
         }
     }
+
+    public static class StringExtensions
+    {
+        public static bool IsNullOrWhiteSpace(string value)
+        {
+            if (value != null)
+            {
+                for (int i = 0; i < value.Length; i++)
+                {
+                    if (!char.IsWhiteSpace(value[i]))
+                    {
+                        return false;
+                    }
+                }
+            }
+            return true;
+        }
+    }
 }
 
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Loading/LoadFiles.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Loading/LoadFiles.cs
index 2e5ddcd..b3a3efe 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Loading/LoadFiles.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Loading/LoadFiles.cs
@@ -21,7 +21,7 @@
                 LoadAndSaveFile(forLoadingFolder + @"\" + fileName, forSavingFolder + @"\" + fileName);
             }
 
-            //LoadAndSaveFile(forLoadingFolder + @"\BasicTable.xlsx", forSavingFolder + @"\BasicTable.xlsx");
+            //LoadAndSaveFile(forLoadingFolder + @"\DataTypes.xlsx", forSavingFolder + @"\DataTypes.xlsx");
         }
 
         private static void LoadAndSaveFile(String input, String output)
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/CellValues.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/CellValues.cs
index 30c7368..6a64845 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/CellValues.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/CellValues.cs
@@ -147,6 +147,27 @@
             ws.Cell(6, 7).Value = stringFormattedString;
 
             //////////////////////////////////////////////////////////////////
+            // TimeSpan
+
+            // Fill a cell with a timeSpan
+            var cellTimeSpan = ws.Cell(7, 2);
+            cellTimeSpan.Value = new TimeSpan(1, 2, 31, 45);
+
+            // Extract the timeSpan in different ways
+            TimeSpan timeSpan1 = (TimeSpan)cellTimeSpan.Value;
+            TimeSpan timeSpan2 = cellTimeSpan.GetTimeSpan();
+            TimeSpan timeSpan3 = cellTimeSpan.GetValue<TimeSpan>();
+            String timeSpanString = cellTimeSpan.GetString();
+            String timeSpanFormattedString = cellTimeSpan.GetFormattedString();
+
+            // Set the values back to cells
+            ws.Cell(7, 3).Value = timeSpan1;
+            ws.Cell(7, 4).Value = timeSpan2;
+            ws.Cell(7, 5).Value = timeSpan3;
+            ws.Cell(7, 6).Value = timeSpanString;
+            ws.Cell(7, 7).Value = timeSpanFormattedString;
+
+            //////////////////////////////////////////////////////////////////
             // Do some formatting
             ws.Columns("B:G").Width = 20;
             var rngTitle = ws.Range("B2:G2");
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Collections.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Collections.cs
index 4296d5f..77e10ac 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Collections.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Collections.cs
@@ -55,7 +55,7 @@
             listOfStrings.Add("House");
             listOfStrings.Add("Car");
             ws.Cell(1, 1).Value = "Strings";
-            ws.Cell(1, 1).Style.Fill.BackgroundColor = Color.Cyan;
+            ws.Cell(1, 1).AsRange().AddToNamed("Titles");
             ws.Cell(2, 1).Value = listOfStrings;
 
             // From a list of arrays
@@ -64,22 +64,20 @@
             listOfArr.Add(new Int32[] { 1 });
             listOfArr.Add(new Int32[] { 1, 2, 3, 4, 5, 6 });
             ws.Cell(1, 3).Value = "Arrays";
-            ws.Cell(1, 3).Style.Fill.BackgroundColor = Color.Cyan;
-            ws.Range(1, 3, 1, 8).Merge();
+            ws.Range(1, 3, 1, 8).Merge().AddToNamed("Titles");
             ws.Cell(2, 3).Value = listOfArr;
 
             // From a DataTable
             var dataTable = GetTable();
             ws.Cell(6, 1).Value = "DataTable";
-            ws.Cell(6, 1).Style.Fill.BackgroundColor = Color.Cyan;
-            ws.Range(6, 1, 6, 4).Merge();
+            ws.Range(6, 1, 6, 4).Merge().AddToNamed("Titles");
             ws.Cell(7, 1).Value = dataTable.AsEnumerable();
 
             // From a query
             var list = new List<Person>();
-            list.Add(new Person() { Name = "John", Age = 30, House = "On Elm St." });
-            list.Add(new Person() { Name = "Mary", Age = 15, House = "On Main St." });
-            list.Add(new Person() { Name = "Luis", Age = 21, House = "On 23rd St." });
+            list.Add(new Person() { Name = "John", Age = 30, House = "On Elm St."   });
+            list.Add(new Person() { Name = "Mary", Age = 15, House = "On Main St."  });
+            list.Add(new Person() { Name = "Luis", Age = 21, House = "On 23rd St."  });
             list.Add(new Person() { Name = "Henry", Age = 45, House = "On 5th Ave." });
 
             var people = from p in list
@@ -87,12 +85,20 @@
                          select new { p.Name, p.House, p.Age };
 
             ws.Cell(6, 6).Value = "Query";
-            ws.Cell(6, 6).Style.Fill.BackgroundColor = Color.Cyan;
-            ws.Range(6, 6, 6, 8).Merge();
+            ws.Range(6, 6, 6, 8).Merge().AddToNamed("Titles");
             ws.Cell(7, 6).Value = people.AsEnumerable();    // Very Important to call the AsEnumerable method
                                                             // otherwise it won't be copied.
 
 
+            // Prepare the style for the titles
+            var titlesStyle = wb.Style;
+            titlesStyle.Font.Bold = true;
+            titlesStyle.Alignment.Horizontal = XLAlignmentHorizontalValues.Center;
+            titlesStyle.Fill.BackgroundColor = Color.Cyan;
+            
+            // Format all titles in one shot
+            wb.NamedRanges.NamedRange("Titles").Ranges.Style = titlesStyle;
+
             ws.Columns().AdjustToContents();
 
             wb.SaveAs(filePath);
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/DataTypes.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/DataTypes.cs
index f65a94e..9b942a7 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/DataTypes.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/DataTypes.cs
@@ -134,7 +134,7 @@
 
             ws.Cell(++ro, co).Value = "Text to TimeSpan:";
             ws.Cell(ro, co + 1).Value = "'" + new TimeSpan(33, 45, 22).ToString();
-            ws.Cell(ro, co + 1).DataType = XLCellValues.Number;
+            ws.Cell(ro, co + 1).DataType = XLCellValues.TimeSpan;
 
             ro++;
 
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Formulas.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Formulas.cs
index 4a6cafc..b466cbd 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Formulas.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Misc/Formulas.cs
@@ -98,7 +98,7 @@
             // And the workbook calculation mode:
             wb.CalculateMode = XLCalculateMode.Auto;
 
-            ws.Range("A10").CreateNamedRange("A10_R1C1_A10_R1C1");
+            ws.Range("A10").AddToNamed("A10_R1C1_A10_R1C1");
             ws.Cell("A10").Value = 0;
             ws.Cell("A11").FormulaA1 = "A2 + A10_R1C1_A10_R1C1";
             ws.Cell("A12").FormulaR1C1 = "R2C1 + A10_R1C1_A10_R1C1";
diff --git a/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/NamedRanges.cs b/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/NamedRanges.cs
index 7be8a15..02e6e7d 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/NamedRanges.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Examples/Ranges/NamedRanges.cs
@@ -30,14 +30,14 @@
             wsData.Cell(4, 2).Value = 29;
 
             // Create a named range with the data:
-            wsData.Range("A2:B4").CreateNamedRange("PeopleData"); // Default named range scope is Workbook
+            wsData.Range("A2:B4").AddToNamed("PeopleData"); // Default named range scope is Workbook
 
             // Let's use the named range in a formula:
             wsPresentation.Cell(1, 1).Value = "People Count:";
             wsPresentation.Cell(1, 2).FormulaA1 = "COUNT(PeopleData)";
 
             // Create a named range with worksheet scope:
-            wsPresentation.Range("B1").CreateNamedRange("PeopleCount", XLScope.Worksheet);
+            wsPresentation.Range("B1").AddToNamed("PeopleCount", XLScope.Worksheet);
 
             // Let's use the named range:
             wsPresentation.Cell(2, 1).Value = "Total:";
diff --git a/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj b/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj
new file mode 100644
index 0000000..97dd3f9
--- /dev/null
+++ b/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj
@@ -0,0 +1,283 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>8.0.30703</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{5F43B12B-A900-40C6-9924-A0C0B032F791}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>ClosedXML</RootNamespace>
+    <AssemblyName>ClosedXML</AssemblyName>
+    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <SccProjectName>SAK</SccProjectName>
+    <SccLocalPath>SAK</SccLocalPath>
+    <SccAuxPath>SAK</SccAuxPath>
+    <SccProvider>SAK</SccProvider>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="DocumentFormat.OpenXml, Version=2.0.5022.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL" />
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Drawing" />
+    <Reference Include="System.Windows.Forms" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+    <Reference Include="WindowsBase" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\ClosedXML\Excel\Cells\IXLCell.cs">
+      <Link>Excel\Cells\IXLCell.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Cells\XLCell.cs">
+      <Link>Excel\Cells\XLCell.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Cells\XLCellCollection.cs">
+      <Link>Excel\Cells\XLCellCollection.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Columns\IXLColumn.cs">
+      <Link>Excel\Columns\IXLColumn.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Columns\IXLColumns.cs">
+      <Link>Excel\Columns\IXLColumns.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Columns\XLColumn.cs">
+      <Link>Excel\Columns\XLColumn.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Columns\XLColumnCollection.cs">
+      <Link>Excel\Columns\XLColumnCollection.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Columns\XLColumnParameters.cs">
+      <Link>Excel\Columns\XLColumnParameters.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Columns\XLColumns.cs">
+      <Link>Excel\Columns\XLColumns.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\IXLAddress.cs">
+      <Link>Excel\IXLAddress.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\IXLOutline.cs">
+      <Link>Excel\IXLOutline.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\IXLWorksheet.cs">
+      <Link>Excel\IXLWorksheet.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\IXLWorksheetInternals.cs">
+      <Link>Excel\IXLWorksheetInternals.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\IXLWorksheets.cs">
+      <Link>Excel\IXLWorksheets.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\NamedRanges\IXLNamedRange.cs">
+      <Link>Excel\NamedRanges\IXLNamedRange.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\NamedRanges\IXLNamedRanges.cs">
+      <Link>Excel\NamedRanges\IXLNamedRanges.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\NamedRanges\XLNamedRange.cs">
+      <Link>Excel\NamedRanges\XLNamedRange.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\NamedRanges\XLNamedRanges.cs">
+      <Link>Excel\NamedRanges\XLNamedRanges.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\IXLHeaderFooter.cs">
+      <Link>Excel\PageSetup\IXLHeaderFooter.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\IXLHFItem.cs">
+      <Link>Excel\PageSetup\IXLHFItem.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\IXLMargins.cs">
+      <Link>Excel\PageSetup\IXLMargins.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\IXLPageSetup.cs">
+      <Link>Excel\PageSetup\IXLPageSetup.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\IXLPrintAreas.cs">
+      <Link>Excel\PageSetup\IXLPrintAreas.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\XLHeaderFooter.cs">
+      <Link>Excel\PageSetup\XLHeaderFooter.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\XLHFItem.cs">
+      <Link>Excel\PageSetup\XLHFItem.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\XLMargins.cs">
+      <Link>Excel\PageSetup\XLMargins.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\XLPageSetup.cs">
+      <Link>Excel\PageSetup\XLPageSetup.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\PageSetup\XLPrintAreas.cs">
+      <Link>Excel\PageSetup\XLPrintAreas.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRange.cs">
+      <Link>Excel\Ranges\IXLRange.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRangeAddress.cs">
+      <Link>Excel\Ranges\IXLRangeAddress.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRangeBase.cs">
+      <Link>Excel\Ranges\IXLRangeBase.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRangeColumn.cs">
+      <Link>Excel\Ranges\IXLRangeColumn.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRangeColumns.cs">
+      <Link>Excel\Ranges\IXLRangeColumns.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRangeRow.cs">
+      <Link>Excel\Ranges\IXLRangeRow.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRangeRows.cs">
+      <Link>Excel\Ranges\IXLRangeRows.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\IXLRanges.cs">
+      <Link>Excel\Ranges\IXLRanges.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRange.cs">
+      <Link>Excel\Ranges\XLRange.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeAddress.cs">
+      <Link>Excel\Ranges\XLRangeAddress.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeBase.cs">
+      <Link>Excel\Ranges\XLRangeBase.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeColumn.cs">
+      <Link>Excel\Ranges\XLRangeColumn.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeColumns.cs">
+      <Link>Excel\Ranges\XLRangeColumns.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeParameters.cs">
+      <Link>Excel\Ranges\XLRangeParameters.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeRow.cs">
+      <Link>Excel\Ranges\XLRangeRow.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRangeRows.cs">
+      <Link>Excel\Ranges\XLRangeRows.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Ranges\XLRanges.cs">
+      <Link>Excel\Ranges\XLRanges.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Rows\IXLRow.cs">
+      <Link>Excel\Rows\IXLRow.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Rows\IXLRows.cs">
+      <Link>Excel\Rows\IXLRows.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Rows\XLRow.cs">
+      <Link>Excel\Rows\XLRow.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Rows\XLRowCollection.cs">
+      <Link>Excel\Rows\XLRowCollection.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Rows\XLRowParameters.cs">
+      <Link>Excel\Rows\XLRowParameters.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Rows\XLRows.cs">
+      <Link>Excel\Rows\XLRows.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLAlignment.cs">
+      <Link>Excel\Style\IXLAlignment.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLBorder.cs">
+      <Link>Excel\Style\IXLBorder.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLFill.cs">
+      <Link>Excel\Style\IXLFill.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLFont.cs">
+      <Link>Excel\Style\IXLFont.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLNumberFormat.cs">
+      <Link>Excel\Style\IXLNumberFormat.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLStyle.cs">
+      <Link>Excel\Style\IXLStyle.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\IXLStylized.cs">
+      <Link>Excel\Style\IXLStylized.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\XLAlignment.cs">
+      <Link>Excel\Style\XLAlignment.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\XLBorder.cs">
+      <Link>Excel\Style\XLBorder.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\XLFill.cs">
+      <Link>Excel\Style\XLFill.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\XLFont.cs">
+      <Link>Excel\Style\XLFont.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\XLNumberFormat.cs">
+      <Link>Excel\Style\XLNumberFormat.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\Style\XLStyle.cs">
+      <Link>Excel\Style\XLStyle.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLAddress.cs">
+      <Link>Excel\XLAddress.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLOutline.cs">
+      <Link>Excel\XLOutline.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorkbook.cs">
+      <Link>Excel\XLWorkbook.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorkbookProperties.cs">
+      <Link>Excel\XLWorkbookProperties.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorkbook_Load.cs">
+      <Link>Excel\XLWorkbook_Load.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorkbook_Save.cs">
+      <Link>Excel\XLWorkbook_Save.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorksheet.cs">
+      <Link>Excel\XLWorksheet.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorksheetInternals.cs">
+      <Link>Excel\XLWorksheetInternals.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Excel\XLWorksheets.cs">
+      <Link>Excel\XLWorksheets.cs</Link>
+    </Compile>
+    <Compile Include="..\ClosedXML\Extensions.cs">
+      <Link>Extensions.cs</Link>
+    </Compile>
+    <Compile Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup />
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>
\ No newline at end of file
diff --git a/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj.vspscc b/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj.vspscc
new file mode 100644
index 0000000..feffdec
--- /dev/null
+++ b/ClosedXML/ClosedXML/ClosedXML_Net3.5/ClosedXML_Net3.5.csproj.vspscc
@@ -0,0 +1,10 @@
+""
+{
+"FILE_VERSION" = "9237"
+"ENLISTMENT_CHOICE" = "NEVER"
+"PROJECT_FILE_RELATIVE_PATH" = ""
+"NUMBER_OF_EXCLUDED_FILES" = "0"
+"ORIGINAL_PROJECT_FILE_PATH" = ""
+"NUMBER_OF_NESTED_PROJECTS" = "0"
+"SOURCE_CONTROL_SETTINGS_PROVIDER" = "PROVIDER"
+}
diff --git a/ClosedXML/ClosedXML/ClosedXML_Net3.5/Properties/AssemblyInfo.cs b/ClosedXML/ClosedXML/ClosedXML_Net3.5/Properties/AssemblyInfo.cs
new file mode 100644
index 0000000..2a775cf
--- /dev/null
+++ b/ClosedXML/ClosedXML/ClosedXML_Net3.5/Properties/AssemblyInfo.cs
@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ClosedXML_Net3.5")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("Microsoft")]
+[assembly: AssemblyProduct("ClosedXML_Net3.5")]
+[assembly: AssemblyCopyright("Copyright © Microsoft 2010")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("d627551d-470d-4a39-a5f1-5a71696b8200")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]