diff --git a/src/TwigExtension/ArcheTwigDateExtension.php b/src/TwigExtension/ArcheTwigDateExtension.php
index e824fe9d..56b87334 100644
--- a/src/TwigExtension/ArcheTwigDateExtension.php
+++ b/src/TwigExtension/ArcheTwigDateExtension.php
@@ -12,7 +12,7 @@ public function getFilters()
             if ($this->checkYearIsMoreThanFourDigit($value)) {
                 return $this->notNormalDate($value, $lang, $dateformat);
             }
-            return $this->returnFormattedDate($this->extendDateFormat($dateformat), $value, $lang);
+            return $this->returnFormattedDate($dateformat, $value, $lang);
         })
         ];
     }
@@ -25,20 +25,6 @@ public function getName()
         return 'acdh_repo_gui.twig_extension';
     }
 
-    /**
-     * change the datefomat to work with strftime
-     *
-     * @param string $dateformat
-     * @return string
-     */
-    private function extendDateFormat(string $dateFormat): string
-    {
-        $search  = array('Y', 'y', 'M', 'm', 'D', 'd');
-        $replace = array('%Y', '%y', '%b', '%m', '%d', '%d');
-
-        return str_replace($search, $replace, $dateFormat);
-    }
-
     private function checkYearIsMoreThanFourDigit($value): bool
     {
         $explode = explode("-", $value);
@@ -57,13 +43,13 @@ private function checkYearIsMoreThanFourDigit($value): bool
      */
     private function returnFormattedDate($dateformat, $value, $lang): string
     {
+        $cal = \IntlCalendar::fromDateTime($value." Europe/Vienna");
         if ($lang == 'de') {
-            setlocale(LC_TIME, 'de_DE.utf8');
-            return strftime($dateformat, strtotime($value));
+            return \IntlDateFormatter::formatObject($cal, $dateformat, 'de_DE');
         }
-        
-        setlocale(LC_TIME, 'en_US.utf8');
-        return strftime($dateformat, strtotime($value));
+        return \IntlDateFormatter::formatObject($cal, $dateformat, 'en_US');
+        //setlocale(LC_TIME, 'en_US.utf8');
+        //return strftime($dateformat, strtotime($value));
     }
 
     
diff --git a/templates/acdh-repo-gui-child.html.twig b/templates/acdh-repo-gui-child.html.twig
index 8cef5c1a..cc7247a6 100644
--- a/templates/acdh-repo-gui-child.html.twig
+++ b/templates/acdh-repo-gui-child.html.twig
@@ -85,7 +85,7 @@
                                 <span class="res-prop-label">{{ "Available Date"|trans }}:</span>
                                 
                                 {{ include('/modules/contrib/arche-gui/templates/helpers/helper-date.html.twig', 
-                                {'value': item.getData('acdh:hasAvailableDate')[0],  'dateformat': 'd M Y' } ) }}
+                                {'value': item.getData('acdh:hasAvailableDate')[0],  'dateformat': 'd MMM Y' } ) }}
                                 
                             {% endif%}
                             {% if item.getData('acdh:hasAvailableDate')[0].value and item.getData('acdh:hasVersion')[0].value %}
diff --git a/templates/acdh-repo-gui-detail-basic.html.twig b/templates/acdh-repo-gui-detail-basic.html.twig
index f1eb6563..480f48ce 100644
--- a/templates/acdh-repo-gui-detail-basic.html.twig
+++ b/templates/acdh-repo-gui-detail-basic.html.twig
@@ -36,19 +36,19 @@
         'icon': 'today',
         'label': 'Created Start Date',
         'type': 'date',
-        'dateformat': 'd M Y'
+        'dateformat': 'd MMM Y'
     },
     'acdh:hasCreatedEndDate': {
         'icon': 'today',
         'label': 'Created End Date',
         'type': 'date',
-        'dateformat': 'd M Y'
+        'dateformat': 'd MMM Y'
     },
     'acdh:hasAvailableDate': {
         'icon': 'today',
         'label': 'Available Date',
         'type': 'date',
-        'dateformat': 'd M Y'
+        'dateformat': 'd MMM Y'
     },
     'acdh:hasExtent': {
         'icon': 'dehaze',
diff --git a/templates/acdh-repo-gui-detail-project.html.twig b/templates/acdh-repo-gui-detail-project.html.twig
index 2609bd42..1ec79fc1 100644
--- a/templates/acdh-repo-gui-detail-project.html.twig
+++ b/templates/acdh-repo-gui-detail-project.html.twig
@@ -20,13 +20,13 @@ set properties = {
         'icon': 'today',
         'label': 'Start Date',
         'type': 'date',
-        'dateformat': 'd M Y'
+        'dateformat': 'd MMM Y'
     },
     'acdh:hasEndDate': {
         'icon': 'today',
         'label': 'End Date',
         'type': 'date',
-        'dateformat': 'd M Y'
+        'dateformat': 'd MMM Y'
     },
     'acdh:hasLanguage': {
         'icon': 'flag',
diff --git a/templates/acdh-repo-gui-detail-versions-block.html.twig b/templates/acdh-repo-gui-detail-versions-block.html.twig
index 3e4c37aa..58471440 100644
--- a/templates/acdh-repo-gui-detail-versions-block.html.twig
+++ b/templates/acdh-repo-gui-detail-versions-block.html.twig
@@ -20,7 +20,7 @@
             {% for key, value in result %}
                 {% set versionTxt = '' %}
                 <div class="pl-2 pb-1 arche-versions-row {{ value.actual }}">
-                    <i class="material-icons" style="font-size:14px !important" >layers</i>&nbsp;<a href="/browser/oeaw_detail/{{ value.id }}">{{ versionTxt|trans }} {{ value.avdate|date('d M Y') }} &ndash; {{ value.version }}</a>
+                    <i class="material-icons" style="font-size:14px !important" >layers</i>&nbsp;<a href="/browser/oeaw_detail/{{ value.id }}">{{ versionTxt|trans }} {{ value.avdate|date('d MMM Y') }} &ndash; {{ value.version }}</a>
                 </div>
             {% endfor %}
         </div>
diff --git a/templates/acdh-repo-gui-main-page-left-block.html.twig b/templates/acdh-repo-gui-main-page-left-block.html.twig
index f1ca2af6..3cadc6c4 100644
--- a/templates/acdh-repo-gui-main-page-left-block.html.twig
+++ b/templates/acdh-repo-gui-main-page-left-block.html.twig
@@ -25,7 +25,7 @@
             {% if item.getData('acdh:hasAvailableDate') %}
                 {{ item.getPropTitle('acdh:hasAvailableDate') }}
                 <div class="res-property">
-                    {{ include('/modules/contrib/arche-gui/templates/helper-displayFields.html.twig', {'data': item.getData('acdh:hasAvailableDate') , 'icon': 'today', 'type': 'date', 'dateformat': "d M Y", 'label': "Available Date"  } ) }}
+                    {{ include('/modules/contrib/arche-gui/templates/helper-displayFields.html.twig', {'data': item.getData('acdh:hasAvailableDate') , 'icon': 'today', 'type': 'date', 'dateformat': "d MMM Y", 'label': "Available Date"  } ) }}
                 </div>
             {% endif%}
 
diff --git a/templates/acdh-repo-gui-main.html.twig b/templates/acdh-repo-gui-main.html.twig
index 119f40a5..f99e0237 100644
--- a/templates/acdh-repo-gui-main.html.twig
+++ b/templates/acdh-repo-gui-main.html.twig
@@ -31,7 +31,7 @@
                         {% if item.getData('acdh:hasAvailableDate') %}
                             {{ item.getPropTitle('acdh:hasAvailableDate') }}
                             <div class="res-property">
-                                {{ include('/modules/contrib/arche-gui/templates/helper-displayFields.html.twig', {'data': item.getData('acdh:hasAvailableDate') , 'icon': 'today', 'dateformat': "d M Y", 'label': "Available Date", 'type': 'date'  } ) }}
+                                {{ include('/modules/contrib/arche-gui/templates/helper-displayFields.html.twig', {'data': item.getData('acdh:hasAvailableDate') , 'icon': 'today', 'dateformat': "d MMM Y", 'label': "Available Date", 'type': 'date'  } ) }}
                             </div>
                         {% endif%}
                     {% endif%}
diff --git a/templates/acdh-repo-gui-search-full.html.twig b/templates/acdh-repo-gui-search-full.html.twig
index b6c9763d..9ee491c1 100644
--- a/templates/acdh-repo-gui-search-full.html.twig
+++ b/templates/acdh-repo-gui-search-full.html.twig
@@ -35,7 +35,7 @@
                     {% if item.getData('acdh:hasAvailableDate') %}
                         {{ item.getPropTitle('acdh:hasAvailableDate') }}
                         <div class="res-property">
-                            {{ include('/modules/contrib/arche-gui/templates/helper-displayFields.html.twig', {'data': item.getData('acdh:hasAvailableDate') , 'icon': 'today', 'dateformat': "d M Y", 'label': "Available Date", 'type': 'date'  } ) }}
+                            {{ include('/modules/contrib/arche-gui/templates/helper-displayFields.html.twig', {'data': item.getData('acdh:hasAvailableDate') , 'icon': 'today', 'dateformat': "d MMM Y", 'label': "Available Date", 'type': 'date'  } ) }}
                         </div>
                     {% endif%}
                 {% endif%}
diff --git a/templates/helper-displayFields.html.twig b/templates/helper-displayFields.html.twig
index bc58c052..b85c7fbf 100644
--- a/templates/helper-displayFields.html.twig
+++ b/templates/helper-displayFields.html.twig
@@ -18,7 +18,7 @@ Field extra type:
 - delimiter (optional): basic is ",", you can use also "<br>"
 - icon: the fontawesome icon name, what will be displayed before the label
 - label: the label what should be displayed before the value
-- dateformat (required just for the date type):  f.e: 'd M Y'
+- dateformat (required just for the date type):  f.e: 'd MMM Y'
 
 -->