diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82fa47e3..2cba4f68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+- Cell formats with escaped spaces were causing incorrect date formatting - [#557](https://github.com/PHPOffice/PhpSpreadsheet/issues/557)
+
 ### Fixed
 
 - Xlsx reader crashed when reading a file with workbook protection - [#553](https://github.com/PHPOffice/PhpSpreadsheet/pull/553)
diff --git a/src/PhpSpreadsheet/Style/NumberFormat.php b/src/PhpSpreadsheet/Style/NumberFormat.php
index 8075af48..63ef20ae 100644
--- a/src/PhpSpreadsheet/Style/NumberFormat.php
+++ b/src/PhpSpreadsheet/Style/NumberFormat.php
@@ -589,7 +589,7 @@ class NumberFormat extends Supervisor
         }
 
         // Convert any other escaped characters to quoted strings, e.g. (\T to "T")
-        $format = preg_replace('/(\\\(.))(?=(?:[^"]|"[^"]*")*$)/u', '"${2}"', $format);
+        $format = preg_replace('/(\\\([^ ]))(?=(?:[^"]|"[^"]*")*$)/u', '"${2}"', $format);
 
         // Get the sections, there can be up to four sections, separated with a semi-colon (but only if not a quoted literal)
         $sections = preg_split('/(;)(?=(?:[^"]|"[^"]*")*$)/u', $format);
diff --git a/tests/data/Style/NumberFormatDates.php b/tests/data/Style/NumberFormatDates.php
index 6fb5cce7..5b74fbed 100644
--- a/tests/data/Style/NumberFormatDates.php
+++ b/tests/data/Style/NumberFormatDates.php
@@ -52,4 +52,14 @@ return [
         22269.0625,
         '[DBNum1][$-804]m"月"d"日";@',
     ],
+    [
+        '07:35:00 AM',
+        43270.315972222,
+        'hh:mm:ss\ AM/PM',
+    ],
+    [
+        '02:29:00 PM',
+        43270.603472222,
+        'hh:mm:ss\ AM/PM',
+    ],
 ];