diff --git a/activerecord/test/cases/attribute_methods_test.rb b/activerecord/test/cases/attribute_methods_test.rb
index 1ae379769f..059dc8cff3 100644
--- a/activerecord/test/cases/attribute_methods_test.rb
+++ b/activerecord/test/cases/attribute_methods_test.rb
@@ -12,6 +12,8 @@ require 'models/contact'
 require 'models/keyboard'
 
 class AttributeMethodsTest < ActiveRecord::TestCase
+  include InTimeZome
+
   fixtures :topics, :developers, :companies, :computers
 
   def setup
@@ -800,18 +802,6 @@ class AttributeMethodsTest < ActiveRecord::TestCase
     Topic.columns.select { |c| [:time, :date, :datetime, :timestamp].include?(c.type) }
   end
 
-  def in_time_zone(zone)
-    old_zone  = Time.zone
-    old_tz    = ActiveRecord::Base.time_zone_aware_attributes
-
-    Time.zone = zone ? ActiveSupport::TimeZone[zone] : nil
-    ActiveRecord::Base.time_zone_aware_attributes = !zone.nil?
-    yield
-  ensure
-    Time.zone = old_zone
-    ActiveRecord::Base.time_zone_aware_attributes = old_tz
-  end
-
   def privatize(method_signature)
     @target.class_eval(<<-private_method, __FILE__, __LINE__ + 1)
       private
diff --git a/activerecord/test/cases/dirty_test.rb b/activerecord/test/cases/dirty_test.rb
index a6a7b2d528..ac1ab801da 100644
--- a/activerecord/test/cases/dirty_test.rb
+++ b/activerecord/test/cases/dirty_test.rb
@@ -27,6 +27,8 @@ class NumericData < ActiveRecord::Base
 end
 
 class DirtyTest < ActiveRecord::TestCase
+  include InTimeZome
+
   # Dummy to force column loads so query counts are clean.
   def setup
     Person.create :first_name => 'foo'
@@ -603,16 +605,4 @@ class DirtyTest < ActiveRecord::TestCase
       assert_equal %w(parrot_id), pirate.changed
       assert_nil pirate.parrot_id_was
     end
-
-    def in_time_zone(zone)
-      old_zone  = Time.zone
-      old_tz    = ActiveRecord::Base.time_zone_aware_attributes
-
-      Time.zone = zone ? ActiveSupport::TimeZone[zone] : nil
-      ActiveRecord::Base.time_zone_aware_attributes = !zone.nil?
-      yield
-    ensure
-      Time.zone = old_zone
-      ActiveRecord::Base.time_zone_aware_attributes = old_tz
-    end
 end
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index cff6689c15..cb1edc4627 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -135,3 +135,16 @@ module LogIntercepter
   end
 end
 
+module InTimeZome
+  def in_time_zone(zone)
+    old_zone  = Time.zone
+    old_tz    = ActiveRecord::Base.time_zone_aware_attributes
+
+    Time.zone = zone ? ActiveSupport::TimeZone[zone] : nil
+    ActiveRecord::Base.time_zone_aware_attributes = !zone.nil?
+    yield
+  ensure
+    Time.zone = old_zone
+    ActiveRecord::Base.time_zone_aware_attributes = old_tz
+  end
+end