diff --git a/rails/app/controllers/ical_controller.rb b/rails/app/controllers/ical_controller.rb
index b63a0a97f..82f4887f7 100644
--- a/rails/app/controllers/ical_controller.rb
+++ b/rails/app/controllers/ical_controller.rb
@@ -41,7 +41,7 @@ def conference
         uid "#{event.event_id}@#{conf.acronym}@pentabarf.org"
         dtstamp Time.now.strftime('%Y%m%dT%H%M%S')
         dtstart event.start_datetime.strftime('%Y%m%dT%H%M%S'), {'TZID'=>tz.timezone}
-        duration sprintf( 'PT%dH%02dM', event.duration.hour, event.duration.min )
+        dtend event.end_datetime.strftime('%Y%m%dT%H%M%S'), {'TZID'=>tz.timezone}
         summary event.title + ( event.subtitle ? " - #{event.subtitle}" : '')
         description event.abstract.to_s.gsub( "\n", '' ).gsub( "\r", '' )
         add_category "Lecture"
diff --git a/rails/app/views/xcal/conference.rxml b/rails/app/views/xcal/conference.rxml
index 96c17ea8f..c7d8727dc 100644
--- a/rails/app/views/xcal/conference.rxml
+++ b/rails/app/views/xcal/conference.rxml
@@ -10,7 +10,6 @@
     xml.tag!( "pentabarf:language-code", event.language )
     xml.dtstart( event.start_datetime.strftime('%Y%m%dT%H%M%S') )
     xml.dtend( event.end_datetime.strftime('%Y%m%dT%H%M%S') )
-    xml.duration( event.duration.strftime('%HH%MM%SS') )
     xml.summary( event.title + ( event.subtitle ? "- #{event.subtitle}" : "" ) )
     xml.description( event.abstract )
     xml.class( "PUBLIC" )