diff -r 4a668dcfa0a0 -r b0b1148b6963 web/data/cubicweb.calendar.css
--- a/web/data/cubicweb.calendar.css	Mon Nov 04 16:06:06 2013 +0100
+++ b/web/data/cubicweb.calendar.css	Tue Dec 17 10:49:17 2013 +0100
@@ -231,6 +231,8 @@
  font-weight:bold;
  padding-bottom:0.2em;
  background: %(incontextBoxBodyBgColor)s;
+ border-top-left-radius: 6px;
+ border-top-right-radius: 6px;
 }
 
 .calendar th.month a{