diff --git a/ChangeLog b/ChangeLog
index fa9073e5c0..f0d83525d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Oct 29 16:56:03 2005  Tadayoshi Funaba  <tadf@dotrb.org>
+
+	* lib/date.rb: added seven predicates sunday? to saturday?.
+
+	* lib/date.rb: added two methods {prev,next}_month,
+	  that are almost same as << and >>.
+
 Thu Oct 27 20:34:43 2005  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* enumerator.c (enumerator_allocate): allow subclassing.
diff --git a/lib/date.rb b/lib/date.rb
index 9d33198235..93419091ae 100644
--- a/lib/date.rb
+++ b/lib/date.rb
@@ -839,6 +839,10 @@ class Date
 
   once :wday
 
+  DAYNAMES.each_with_index do |n, i|
+    define_method(n.downcase + '?'){wday == i}
+  end
+
   # Is the current date old-style (Julian Calendar)?
   def os? () self.class.os?(jd, @sg) end
 
@@ -969,6 +973,9 @@ class Date
   # of the returned Date will be the last day of the target month.
   def << (n) self >> -n end
 
+  def next_month(n=1) self >> n end
+  def prev_month(n=1) self << n end
+
   # Step the current date forward +step+ days at a
   # time (or backward, if +step+ is negative) until
   # we reach +limit+ (inclusive), yielding the resultant