diff --git a/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/Excel/XLWorkbook_Load.cs
index 0e29be5..75f9cee 100644
--- a/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -95,7 +95,7 @@
             }
 
             var wbProps = dSpreadsheet.WorkbookPart.Workbook.WorkbookProperties;
-            Use1904DateSystem = wbProps != null && wbProps.Date1904 != null && wbProps.Date1904.Value;
+            Use1904DateSystem = wbProps?.Date1904?.Value ?? false;
 
             var wbProtection = dSpreadsheet.WorkbookPart.Workbook.WorkbookProtection;
             if (wbProtection != null)
@@ -1392,6 +1392,13 @@
                     xlCell.DataType = GetDataTypeFromCell(xlCell.Style.NumberFormat);
                 }
             }
+
+            if (Use1904DateSystem && xlCell.DataType == XLDataType.DateTime)
+            {
+                // Internally ClosedXML stores cells as standard 1900-based style
+                // so if a workbook is in 1904-format, we do that adjustment here and when saving.
+                xlCell.SetValue(xlCell.GetDateTime().AddDays(1462));
+            }
         }
 
         /// <summary>
diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index 473956c..a0e3fdc 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -5346,7 +5346,16 @@
                 if (!String.IsNullOrWhiteSpace(xlCell.InnerText))
                 {
                     var cellValue = new CellValue();
-                    cellValue.Text = Double.Parse(xlCell.InnerText, XLHelper.NumberStyle, XLHelper.ParseCulture).ToInvariantString();
+                    var d = Double.Parse(xlCell.InnerText, XLHelper.NumberStyle, XLHelper.ParseCulture);
+
+                    if (xlCell.Worksheet.Workbook.Use1904DateSystem && xlCell.DataType == XLDataType.DateTime)
+                    {
+                        // Internally ClosedXML stores cells as standard 1900-based style
+                        // so if a workbook is in 1904-format, we do that adjustment here and when loading.
+                        d -= 1462;
+                    }
+
+                    cellValue.Text = d.ToInvariantString();
                     openXmlCell.CellValue = cellValue;
                 }
             }
diff --git a/ClosedXML_Tests/ClosedXML_Tests.csproj b/ClosedXML_Tests/ClosedXML_Tests.csproj
index 1365f8a..cf928a7 100644
--- a/ClosedXML_Tests/ClosedXML_Tests.csproj
+++ b/ClosedXML_Tests/ClosedXML_Tests.csproj
@@ -290,6 +290,7 @@
     <EmbeddedResource Include="Resource\Misc\ExcelProducedWorkbookWithImages.xlsx" />
     <EmbeddedResource Include="Resource\Misc\EmptyCellValue.xlsx" />
     <EmbeddedResource Include="Resource\Misc\AllShapes.xlsx" />
+    <EmbeddedResource Include="Resource\Misc\Date1904System.xlsx" />
     <EmbeddedResource Include="Resource\Misc\DuplicateImageNames.xlsx" />
     <EmbeddedResource Include="Resource\Misc\TableHeadersWithLineBreaks.xlsx" />
     <EmbeddedResource Include="Resource\Misc\TableWithNameNull.xlsx" />
diff --git a/ClosedXML_Tests/Excel/Loading/LoadingTests.cs b/ClosedXML_Tests/Excel/Loading/LoadingTests.cs
index 87d5960..64ab73c 100644
--- a/ClosedXML_Tests/Excel/Loading/LoadingTests.cs
+++ b/ClosedXML_Tests/Excel/Loading/LoadingTests.cs
@@ -33,7 +33,8 @@
                 @"Misc\TableHeadersWithLineBreaks.xlsx",
                 @"Misc\TableWithNameNull.xlsx",
                 @"Misc\DuplicateImageNames.xlsx",
-                @"Misc\InvalidPrintArea.xlsx"
+                @"Misc\InvalidPrintArea.xlsx",
+                @"Misc\Date1904System.xlsx"
             };
 
             foreach (var file in files)
@@ -55,6 +56,35 @@
         }
 
         [Test]
+        public void CanLoadDate1904SystemCorrectly()
+        {
+            using (var stream = TestHelper.GetStreamFromResource(TestHelper.GetResourcePath(@"Misc\Date1904System.xlsx")))
+            using (var ms = new MemoryStream())
+            {
+                using (var wb = new XLWorkbook(stream))
+                {
+                    var ws = wb.Worksheets.First();
+                    var c = ws.Cell("A2");
+                    Assert.AreEqual(XLDataType.DateTime, c.DataType);
+                    Assert.AreEqual(new DateTime(2017, 10, 27, 21, 0, 0), c.GetDateTime());
+                    wb.SaveAs(ms);
+                }
+
+                ms.Seek(0, SeekOrigin.Begin);
+
+                using (var wb = new XLWorkbook(ms))
+                {
+                    var ws = wb.Worksheets.First();
+                    var c = ws.Cell("A2");
+                    Assert.AreEqual(XLDataType.DateTime, c.DataType);
+                    Assert.AreEqual(new DateTime(2017, 10, 27, 21, 0, 0), c.GetDateTime());
+                    wb.SaveAs(ms);
+                }
+
+            }
+        }
+
+        [Test]
         public void CanLoadAndSaveFileWithMismatchingSheetIdAndRelId()
         {
             // This file's workbook.xml contains:
@@ -94,7 +124,7 @@
 
         /// <summary>
         /// For non-English locales, the default style ("Normal" in English) can be
-        /// another piece of text (e.g. Обычный in Russian).
+        /// another piece of text (e.g. ??????? in Russian).
         /// This test ensures that the default style is correctly detected and
         /// no style conflicts occur on save.
         /// </summary>
diff --git a/ClosedXML_Tests/Resource/Misc/Date1904System.xlsx b/ClosedXML_Tests/Resource/Misc/Date1904System.xlsx
new file mode 100644
index 0000000..8a7da48
--- /dev/null
+++ b/ClosedXML_Tests/Resource/Misc/Date1904System.xlsx
Binary files differ