diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/CalcEngine/Functions/Logical.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/CalcEngine/Functions/Logical.cs
index 391fed9..1b6695e 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/CalcEngine/Functions/Logical.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/CalcEngine/Functions/Logical.cs
@@ -12,7 +12,7 @@
             ce.RegisterFunction("AND", 1, int.MaxValue, And);
             ce.RegisterFunction("OR", 1, int.MaxValue, Or);
             ce.RegisterFunction("NOT", 1, Not);
-            ce.RegisterFunction("IF", 3, If);
+            ce.RegisterFunction("IF", 2, 3, If);
             ce.RegisterFunction("TRUE", 0, True);
             ce.RegisterFunction("FALSE", 0, False);
         }
@@ -41,9 +41,14 @@
         }
         static object If(List<Expression> p)
         {
-            return (bool)p[0] 
-                ? p[1].Evaluate() 
-                : p[2].Evaluate();
+            if ((bool)p[0] )
+            {
+                return p[1].Evaluate();
+            }
+            else
+            {
+                return p.Count > 2 ? p[2].Evaluate() : false;
+            }
         }
         static object True(List<Expression> p)
         {
diff --git a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
index e7a6c06..94a3a32 100644
--- a/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
+++ b/ClosedXML/ClosedXML/ClosedXML/Excel/Cells/XLCell.cs
@@ -1642,6 +1642,9 @@
                 }
                 else if (value is TimeSpan || (!Double.TryParse(val, out dTest) && TimeSpan.TryParse(val, out tsTest)))
                 {
+                    if (!(value is TimeSpan) && TimeSpan.TryParse(val, out tsTest))
+                        val = tsTest.ToString();
+
                     _dataType = XLCellValues.TimeSpan;
                     if (style.NumberFormat.Format == String.Empty && style.NumberFormat.NumberFormatId == 0)
                         Style.NumberFormat.NumberFormatId = 46;
diff --git a/ClosedXML/ClosedXML/ClosedXML_Tests/ClosedXML_Tests.csproj b/ClosedXML/ClosedXML/ClosedXML_Tests/ClosedXML_Tests.csproj
index 3872960..2e26442 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Tests/ClosedXML_Tests.csproj
+++ b/ClosedXML/ClosedXML/ClosedXML_Tests/ClosedXML_Tests.csproj
@@ -114,6 +114,7 @@
     <Compile Include="Examples\RowsTests.cs" />
     <Compile Include="Examples\StylesTests.cs" />
     <Compile Include="ExcelDocsComparerTests.cs" />
+    <Compile Include="Excel\CalcEngine\LogicalTests.cs" />
     <Compile Include="Excel\CalcEngine\TextTests.cs" />
     <Compile Include="XLHelperTests.cs" />
     <Compile Include="Excel\AutoFilters\AutoFilterTests.cs" />
diff --git a/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/FunctionsTests.cs b/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/FunctionsTests.cs
index 4b89d09..8758174 100644
--- a/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/FunctionsTests.cs
+++ b/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/FunctionsTests.cs
@@ -4,9 +4,7 @@
 
 namespace ClosedXML_Tests.Excel.CalcEngine
 {
-    /// <summary>
-    ///     Summary description for UnitTest1
-    /// </summary>
+
     [TestFixture]
     public class FunctionsTests
     {
diff --git a/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/LogicalTests.cs b/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/LogicalTests.cs
new file mode 100644
index 0000000..c3aeee4
--- /dev/null
+++ b/ClosedXML/ClosedXML/ClosedXML_Tests/Excel/CalcEngine/LogicalTests.cs
@@ -0,0 +1,37 @@
+using System;
+using ClosedXML.Excel;
+using NUnit.Framework;
+
+namespace ClosedXML_Tests.Excel.CalcEngine
+{
+
+    [TestFixture]
+    public class LogicalTests
+    {
+        [Test]
+        public void If_2_Params_true()
+        {
+            Object actual = XLWorkbook.EvaluateExpr(@"if(1 = 1, ""T"")");
+            Assert.AreEqual("T", actual);
+        }
+        [Test]
+        public void If_2_Params_false()
+        {
+            Object actual = XLWorkbook.EvaluateExpr(@"if(1 = 2, ""T"")");
+            Assert.AreEqual(false, actual);
+        }
+
+        [Test]
+        public void If_3_Params_true()
+        {
+            Object actual = XLWorkbook.EvaluateExpr(@"if(1 = 1, ""T"", ""F"")");
+            Assert.AreEqual("T", actual);
+        }
+        [Test]
+        public void If_3_Params_false()
+        {
+            Object actual = XLWorkbook.EvaluateExpr(@"if(1 = 2, ""T"", ""F"")");
+            Assert.AreEqual("F", actual);
+        }
+    }
+}
\ No newline at end of file