diff --git a/src/Spout/Writer/XLSX/Manager/WorksheetManager.php b/src/Spout/Writer/XLSX/Manager/WorksheetManager.php
index 61b93a1..4752239 100644
--- a/src/Spout/Writer/XLSX/Manager/WorksheetManager.php
+++ b/src/Spout/Writer/XLSX/Manager/WorksheetManager.php
@@ -237,6 +237,8 @@ EOD;
 
         if ($cell->isString()) {
             $cellXML .= $this->getCellXMLFragmentForNonEmptyString($cell->getValue());
+        } elseif ($cell->isDate()) {
+            $cellXML .= ' t="d"><v>' . $cell->getValue()->format(\DateTimeInterface::ATOM) . '</v></c>';
         } elseif ($cell->isBoolean()) {
             $cellXML .= ' t="b"><v>' . (int) ($cell->getValue()) . '</v></c>';
         } elseif ($cell->isNumeric()) {
diff --git a/tests/Spout/Writer/XLSX/WriterTest.php b/tests/Spout/Writer/XLSX/WriterTest.php
index 26b3792..1948ffe 100644
--- a/tests/Spout/Writer/XLSX/WriterTest.php
+++ b/tests/Spout/Writer/XLSX/WriterTest.php
@@ -365,7 +365,7 @@ class WriterTest extends TestCase
     {
         $fileName = 'test_add_row_should_support_multiple_types_of_data.xlsx';
         $dataRows = $this->createRowsFromValues([
-            ['xlsx--11', true, '', 0, 10.2, null],
+            ['xlsx--11', true, '', 0, 10.2, null, new \DateTime('2021-01-01'), new \DateTimeImmutable('2021-02-02')],
         ]);
 
         $this->writeToXLSXFile($dataRows, $fileName, $shouldUseInlineStrings = false);