use teh german date format

prolefeeder.py

@@ -25,7 +25,7 @@ attachment_filenames = {}
 class DownloadForm(FlaskForm):
     start_time = DateTimeField('Startzeit',
                                validators=[InputRequired()],
-                               format='%Y-%m-%d %H:%M')
+                               format='%d.%m.%Y %H:%M')
     length = IntegerField('Länge',
                           validators=[
                               InputRequired(),

templates/download.html

@@ -28,7 +28,12 @@
         <div class="form-group required {% if form.start_time.errors %}has-error{% endif -%}">
             {{ form.start_time.label(class_="control-label") }}
             <div class='input-group' id='start_time_group'>
-                <input name='start_time' id='start_time_' class="form-control" value="{{ form.start_time.data }}"/>
+                <input name='start_time' id='start_time_' class="form-control"
+                    placeholder="{{ form.start_time.format }}"
+                    {% if form.start_time.data %}
+                    value="{{ form.start_time.data.strftime(form.start_time.format) }}"
+                    {% endif %}
+                />
                 <span class="input-group-addon">
                     <span class="glyphicon glyphicon-calendar"></span>
                 </span>
@@ -67,7 +72,7 @@
     $(document).ready(function() {
         $('#start_time_group').datetimepicker({
             locale: 'de',
-            format: 'YYYY-MM-DD HH:mm',
+            format: 'DD.MM.YYYY HH:mm',
             sideBySide: true
         });
         $(".alert-success").delay(4000).fadeOut(500, function() {