--- a/web/httpcache.py	Fri Dec 09 12:08:27 2011 +0100
+++ b/web/httpcache.py	Thu Jan 19 12:57:02 2012 +0100
@@ -23,6 +23,7 @@
 from datetime import datetime
 
 # time delta usable to convert localized time to GMT time
+# XXX this become erroneous after a DST transition!!!
 GMTOFFSET = - (datetime.now() - datetime.utcnow())
 
 class NoHTTPCacheManager(object):