diff --git a/src/Hackspace/Bundle/CalciferBundle/Controller/EventController.php b/src/Hackspace/Bundle/CalciferBundle/Controller/EventController.php
index b999599..78bfb9e 100755
--- a/src/Hackspace/Bundle/CalciferBundle/Controller/EventController.php
+++ b/src/Hackspace/Bundle/CalciferBundle/Controller/EventController.php
@@ -63,7 +63,8 @@ class EventController extends Controller
         $em = $this->saveEvent($request, $entity);
 
 
-        if ($entity->isValid()) {
+        $errors = $entity->isValid();
+        if ($errors === true) {
             $em = $this->getDoctrine()->getManager();
             $em->persist($entity);
             $em->flush();
@@ -73,6 +74,7 @@ class EventController extends Controller
 
         return array(
             'entity' => $entity,
+            'errors' => $errors,
         );
     }
 
@@ -171,7 +173,8 @@ class EventController extends Controller
         $em = $this->saveEvent($request, $entity);
 
 
-        if ($entity->isValid()) {
+        $errors = $entity->isValid();
+        if ($errors === true) {
             $em = $this->getDoctrine()->getManager();
             $em->persist($entity);
             $em->flush();
@@ -180,7 +183,8 @@ class EventController extends Controller
         }
 
         return array(
-            'entity'      => $entity,
+            'entity' => $entity,
+            'errors' => $errors,
 
         );
     }
@@ -199,8 +203,10 @@ class EventController extends Controller
         $entity->summary = $request->get('summary');
         $entity->url = $request->get('url');
         $startdate = $request->get('startdate');
-        $startdate = new \DateTime($startdate);
-        $entity->startdate = $startdate;
+        if (strlen($startdate) > 0) {
+            $startdate = new \DateTime($startdate);
+            $entity->startdate = $startdate;
+        }
         $entity->slug = $entity->generateSlug($entity->summary,$em);
 
         $enddate = $request->get('enddate');
@@ -267,7 +273,6 @@ class EventController extends Controller
                     $entity->addTag($tag_obj);
                 }
             }
-            return $em;
         }
         return $em;
     }
diff --git a/src/Hackspace/Bundle/CalciferBundle/Entity/BaseEntity.php b/src/Hackspace/Bundle/CalciferBundle/Entity/BaseEntity.php
index a33a608..ba972ee 100755
--- a/src/Hackspace/Bundle/CalciferBundle/Entity/BaseEntity.php
+++ b/src/Hackspace/Bundle/CalciferBundle/Entity/BaseEntity.php
@@ -56,7 +56,11 @@ abstract class BaseEntity {
 
     public function __set($name,$value) {
         if (property_exists($this,$name)) {
-            $this->$name = $value;
+            if ($value == '') {
+                $this->$name = null;
+            } else {
+                $this->$name = $value;
+            }
             return $this;
         } else {
             throw new \Exception("Property {$name} does not Exists");
diff --git a/src/Hackspace/Bundle/CalciferBundle/Entity/Event.php b/src/Hackspace/Bundle/CalciferBundle/Entity/Event.php
index 8a3a791..68104d4 100755
--- a/src/Hackspace/Bundle/CalciferBundle/Entity/Event.php
+++ b/src/Hackspace/Bundle/CalciferBundle/Entity/Event.php
@@ -3,6 +3,7 @@
 namespace Hackspace\Bundle\CalciferBundle\Entity;
 
 use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Validator\Constraints\DateTime;
 
 /**
  * Event
@@ -102,7 +103,18 @@ class Event extends BaseEntity
     }
 
     public function isValid() {
-        return true;
+        $errors = [];
+        if (!($this->startdate instanceof \DateTime)) {
+            $errors['startdate'] = 'Bitte gebe ein Startdatum ein.';
+        }
+        if ((!is_null($this->startdate)) && (!is_null($this->enddate)) && ($this->enddate < $this->startdate)) {
+            $errors['enddate'] = 'Bitte setze ein Enddatum das nach dem Startdatum ist.';
+        }
+        if (strlen($this->summary) == 0) {
+            $errors['summary'] = 'Bitte gebe eine Zusammenfassung an.';
+        }
+
+        return (count($errors) > 0) ? $errors : true;
     }
 
     public function getFormatedDate() {
diff --git a/src/Hackspace/Bundle/CalciferBundle/Resources/views/Event/event_form.html.twig b/src/Hackspace/Bundle/CalciferBundle/Resources/views/Event/event_form.html.twig
index d2f1e82..39ac995 100755
--- a/src/Hackspace/Bundle/CalciferBundle/Resources/views/Event/event_form.html.twig
+++ b/src/Hackspace/Bundle/CalciferBundle/Resources/views/Event/event_form.html.twig
@@ -1,6 +1,6 @@
 <form method="post" action="{% if entity.id|default(0) > 0 %}{{ path('_update',{'slug':entity.slug}) }}{% else %}{{ path('_create') }}{% endif %}">
     <div class="ui form segment">
-        <div class="field">
+        <div class="field{% if(errors|default('0') != 0) %} {% if('startdate' in errors|keys) %}error{% endif %}{% endif %}">
             <label class="control-label required" for="event_startdate">Startdatum</label>
 
             <div class="ui left labeled icon input">
@@ -11,6 +11,9 @@
                        value="{{ entity.startdate.format('Y-m-d H:i')|default('') }}"
                        placeholder="{{ "now"|date('Y-m-d H:i') }}"
                        class="form-control">
+                {% if(errors|default('0') != 0) %} {% if('startdate' in errors|keys) %}
+                <div class="ui red pointing above ui label">{{ errors.startdate }}</div>
+                {% endif %}{% endif %}
 
                 <i class="icon calendar"></i>
 
@@ -19,7 +22,7 @@
                 </div>
             </div>
         </div>
-        <div class="field">
+        <div class="field{% if(errors|default('0') != 0) %} {% if('enddate' in errors|keys) %}error{% endif %}{% endif %}">
             <label class="control-label required" for="event_enddate">Enddatum</label>
 
             <div class="ui left labeled icon input">
@@ -30,10 +33,14 @@
                        placeholder="{{ "now"|date('Y-m-d H:i') }}"
                        class="form-control">
 
+                {% if(errors|default('0') != 0) %} {% if('enddate' in errors|keys) %}
+                    <div class="ui red pointing above ui label">{{ errors.enddate }}</div>
+                {% endif %}{% endif %}
+
                 <i class="icon calendar"></i>
             </div>
         </div>
-        <div class="field">
+        <div class="field{% if(errors|default('0') != 0) %} {% if('summary' in errors|keys) %}error{% endif %}{% endif %}">
             <label class="" for="event_summary">Zusammenfassung</label>
 
             <div class="ui left labeled input">
@@ -45,6 +52,10 @@
                        maxlength="255"
                        class="form-control">
 
+                {% if(errors|default('0') != 0) %} {% if('summary' in errors|keys) %}
+                    <div class="ui red pointing above ui label">{{ errors.summary }}</div>
+                {% endif %}{% endif %}
+
                 <div class="ui corner label">
                     <i class="icon asterisk"></i>
                 </div>