diff --git a/ChangeLog b/ChangeLog
index 1adba71b2a..c7c8253a5c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Jul 17 18:24:22 2011  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* lib/date.rb (complete_frags): Monday must be suitable for %W's
+	  default day.
+
 Sun Jul 17 17:52:19 2011  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* numeric.c (flo_cmp): Infinity is greater than any bignum
diff --git a/lib/date.rb b/lib/date.rb
index 55d0d0c118..8e0096e295 100644
--- a/lib/date.rb
+++ b/lib/date.rb
@@ -879,7 +879,7 @@ class Date
 	  elem[e] = d.__send__(e)
 	end
 	elem[:wnum1] ||= 0
-	elem[:wday]  ||= 0
+	elem[:wday]  ||= 1
       end
     end