diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index f6b09c84d9..402afa237f 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added Time#end_of_day to get 23:59:59 of that day [DHH]
+
 * Don't quote hash keys in Hash#to_json if they're valid JavaScript identifiers.  Disable this with ActiveSupport::JSON.unquote_hash_key_identifiers = false if you need strict JSON compliance. [Sam Stephenson]
 
 * Lazily load the Unicode Database in the UTF-8 Handler [Rick Olson]
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index fb82513047..cdfcdf57d7 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -149,6 +149,11 @@ module ActiveSupport #:nodoc:
         alias :at_midnight :beginning_of_day
         alias :at_beginning_of_day :beginning_of_day
         
+        # Returns a new Time representing the end of the day (23:59:59)
+        def end_of_day
+          change(:hour => 23, :minute => 59, :sec => 59)
+        end
+        
         # Returns a new Time representing the start of the month (1st of the month, 0:00)
         def beginning_of_month
           #self - ((self.mday-1).days + self.seconds_since_midnight)