diff --git a/activesupport/lib/active_support/core_ext/date/calculations.rb b/activesupport/lib/active_support/core_ext/date/calculations.rb
index ce3bebc25a..3dd61334d0 100644
--- a/activesupport/lib/active_support/core_ext/date/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/date/calculations.rb
@@ -1,4 +1,5 @@
 require 'active_support/duration'
+require 'active_support/core_ext/time/zones'
 
 class Date
   class << self
diff --git a/activesupport/lib/active_support/core_ext/date/conversions.rb b/activesupport/lib/active_support/core_ext/date/conversions.rb
index 54facf4430..b41ad5b686 100644
--- a/activesupport/lib/active_support/core_ext/date/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/date/conversions.rb
@@ -1,6 +1,7 @@
 require 'active_support/inflector'
 require 'active_support/core_ext/time/conversions'
 require 'active_support/core_ext/date_time/conversions'
+require 'active_support/values/time_zone'
 
 class Date
   DATE_FORMATS = {
diff --git a/activesupport/lib/active_support/json/encoding.rb b/activesupport/lib/active_support/json/encoding.rb
index f440d6ce58..8e8f9022c1 100644
--- a/activesupport/lib/active_support/json/encoding.rb
+++ b/activesupport/lib/active_support/json/encoding.rb
@@ -6,10 +6,7 @@
 require 'active_support/core_ext/object/instance_variables'
 require 'active_support/deprecation'
 
-require 'active_support/core_ext/date_time/conversions'
-require 'active_support/core_ext/time/conversions'
 require 'active_support/time_with_zone'
-require 'active_support/values/time_zone'
 
 # Hack to load json gem first so we can overwrite its to_json.
 begin
diff --git a/activesupport/lib/active_support/time_with_zone.rb b/activesupport/lib/active_support/time_with_zone.rb
index 4907fae9d6..a64128e49e 100644
--- a/activesupport/lib/active_support/time_with_zone.rb
+++ b/activesupport/lib/active_support/time_with_zone.rb
@@ -1,4 +1,5 @@
 require 'active_support/duration'
+require 'active_support/values/time_zone'
 require 'active_support/core_ext/numeric/time'
 require 'active_support/core_ext/integer/time'
 require 'active_support/core_ext/time/conversions'
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index 892aa97ad7..6a51ce9402 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -154,13 +154,13 @@ def test_expires_in
     File.stubs(:mtime).returns(time)
 
     @cache.write('foo', 'bar')
-    cache_read = lambda { @cache.read('foo', :expires_in => 1.minute) }
+    cache_read = lambda { @cache.read('foo', :expires_in => 60) }
     assert_equal 'bar', cache_read.call
 
-    Time.stubs(:now).returns(time + 30.seconds)
+    Time.stubs(:now).returns(time + 30)
     assert_equal 'bar', cache_read.call
 
-    Time.stubs(:now).returns(time + 2.minutes)
+    Time.stubs(:now).returns(time + 120)
     assert_nil cache_read.call
   end
 end
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index 26a55a73e1..af73b08547 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -242,6 +242,7 @@ def new
     # If assigned value cannot be matched to a TimeZone, an exception will be raised.
     initializer :initialize_time_zone do
       if config.time_zone
+        require 'active_support/core_ext/time/zones'
         zone_default = Time.__send__(:get_zone, config.time_zone)
 
         unless zone_default