Improve section heading for date/time history.

diff --git a/doc/src/sgml/datetime.sgml b/doc/src/sgml/datetime.sgml
index dcc63d5564657381f35c0ced4a9f5da181bef56b..0ebdd14d91e5af123cfab0abb50bfc15582415bf 100644 (file)
--- a/doc/src/sgml/datetime.sgml
+++ b/doc/src/sgml/datetime.sgml
@@ -1,5 +1,5 @@
 
 
@@ -624,7 +624,7 @@ Date/time details
  
 
  
-  History
+  History<span class="marked"> of Units</span>