diff --git a/content/events.xml b/content/events.xml
index 0ae6cdd16..56764677a 100644
--- a/content/events.xml
+++ b/content/events.xml
@@ -27,4 +27,10 @@
     <location>global</location>
     <link>http://de.wikipedia.org/wiki/Kauf-Nix-Tag</link>
   </event>
+  <event title="23C3">
+    <start>2006-12-27</start>
+    <end>2006-12-30</end>
+    <location>Berlin</location>
+    <link>http://www.ccc.de/congress/</link>
+  </event>
 </calendar>
diff --git a/xsl/calendar-summary.xsl b/xsl/calendar-summary.xsl
index 6094b8cf9..a3e4d4a58 100644
--- a/xsl/calendar-summary.xsl
+++ b/xsl/calendar-summary.xsl
@@ -39,7 +39,17 @@
           </xsl:otherwise>
         </xsl:choose>
       </title>
-      <date><xsl:value-of select="start"/></date>
+      <start><xsl:value-of select="start"/></start>
+      <end>
+        <xsl:choose>
+          <xsl:when test="end">
+            <xsl:value-of select="end"/>
+          </xsl:when>
+          <xsl:otherwise>
+            <xsl:value-of select="start"/>
+          </xsl:otherwise>
+        </xsl:choose>
+      </end>
       <location><xsl:value-of select="location"/></location>
       <link>
         <xsl:choose>
diff --git a/xsl/calendar.xsl b/xsl/calendar.xsl
index f35bfaacd..d40e09c91 100644
--- a/xsl/calendar.xsl
+++ b/xsl/calendar.xsl
@@ -73,8 +73,13 @@
     </span>
     <ul>
       <xsl:for-each select="event">
-        <xsl:sort select="date"/>
-        <xsl:if test="concat(date:year($date),'-',date:month-in-year($date),'-',date:day-in-month($date)) = concat(date:year(date),'-',date:month-in-year(date),'-',date:day-in-month(date))">
+        <xsl:sort select="start"/>
+
+        <xsl:variable name="start" select="concat(format-number(date:year(start),'00'),format-number(date:month-in-year(start),'00'),format-number(date:day-in-month(start),'00'))"/>
+        <xsl:variable name="end" select="concat(format-number(date:year(end),'00'),format-number(date:month-in-year(end),'00'),format-number(date:day-in-month(end),'00'))"/>
+        <xsl:variable name="date" select="concat(format-number(date:year($date),'00'),format-number(date:month-in-year($date),'00'),format-number(date:day-in-month($date),'00'))"/>
+
+        <xsl:if test="($start &lt;= $date) and ($date &lt;= $end)">
           <li>
             <a href="{link}">
               <xsl:value-of select="title"/>