Corrected date time detection (#1492)

* Corrected date time detection

German and Swiss ZIP codes (special formats provided in German Excel versions) were detected as date time value, because the regular expression for date time formats falsely matched their formats ("\C\H\-00000" and "\D-00000").

Author: Christoph Ziegenberg

src/PhpSpreadsheet/Shared/Date.php

@@ -387,6 +387,11 @@ public static function isDateTimeFormatCode($pFormatCode)
         if ((substr($pFormatCode, 0, 1) == '_') || (substr($pFormatCode, 0, 2) == '0 ')) {
             return false;
         }
+        // Some "special formats" provided in German Excel versions were detected as date time value,
+        // so filter them out here - "\C\H\-00000" (Switzerland) and "\D-00000" (Germany).
+        if (\strpos($pFormatCode, '-00000') !== false) {
+            return false;
+        }
         // Try checking for any of the date formatting characters that don't appear within square braces
         if (preg_match('/(^|\])[^\[]*[' . self::$possibleDateFormatCharacters . ']/i', $pFormatCode)) {
             //    We might also have a format mask containing quoted strings...

tests/data/Shared/Date/FormatCodes.php

@@ -150,4 +150,12 @@
         true,
         '"date " y-m-d',
     ],
+    [
+        false,
+        '\C\H\-00000',
+    ],
+    [
+        false,
+        '\D-00000',
+    ],
 ];