diff --git a/ChangeLog b/ChangeLog
index 4900ea7c25..5cdf1ccb14 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Nov 23 07:27:27 2010  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* lib/date.rb (daynum): should be private.
+
 Tue Nov 23 07:22:54 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ChangeLog (change-log-indent-text): hunging indent.
diff --git a/lib/date.rb b/lib/date.rb
index f8d4538ec5..43814792f7 100644
--- a/lib/date.rb
+++ b/lib/date.rb
@@ -1144,6 +1144,7 @@ class Date
   def daynum() ajd_to_jd(@ajd, @of) end
 
   once :daynum
+  private :daynum
 
   # Get the date as a Julian Day Number.
   def jd() daynum[0] end