Cleaner datetime localization for xml output

app/views/events/index.xml.builder

@@ -4,8 +4,8 @@ xml.events do
   @events.find_each do |event|
     xml.event do
       xml.title event.title
-      xml.tag! 'start-time', event.start_time.strftime('%Y/%m/%d %T')
-      xml.tag! 'end-time', event.end_time.strftime('%Y/%m/%d %T')
+      xml.tag! 'start-time', l(event.start_time, format: 'xml')
+      xml.tag! 'end-time', l(event.end_time, format: 'xml')
       xml.place_name event.place_name
       xml.address event.address
       xml.city event.city

config/locales/fr.yml

@@ -9,3 +9,4 @@ fr:
     formats:
       at: '%A %e %B %Y à %Hh%M'
       hours: '%Hh%M'
+      xml: '%Y/%m/%d %T'