diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index 2cce782..785d84e 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -208,7 +208,7 @@ module ActiveSupport #:nodoc:
 
         # Returns a new Time representing the end of the quarter (last day of march, june, september, december, 23:59:59)
         def end_of_quarter
-          change(:month => [3, 6, 9, 12].detect { |m| m >= self.month }).end_of_month
+          beginning_of_month.change(:month => [3, 6, 9, 12].detect { |m| m >= self.month }).end_of_month
         end
         alias :at_end_of_quarter :end_of_quarter
 
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index e53b719..ef88526 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -117,6 +117,7 @@ class TimeExtCalculationsTest < Test::Unit::TestCase
     assert_equal Time.local(2007,3,31,23,59,59), Time.local(2007,3,31,0,0,0).end_of_quarter
     assert_equal Time.local(2007,12,31,23,59,59), Time.local(2007,12,21,10,10,10).end_of_quarter
     assert_equal Time.local(2007,6,30,23,59,59), Time.local(2007,4,1,0,0,0).end_of_quarter
+    assert_equal Time.local(2008,6,30,23,59,59), Time.local(2008,5,31,0,0,0).end_of_quarter
   end
 
   def test_end_of_year