diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 8a65945e61..ec49d40a12 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1,6 +1,7 @@
 require 'yaml'
 require 'set'
 require 'active_support/dependencies'
+require 'active_support/time'
 require 'active_support/core_ext/class/attribute_accessors'
 require 'active_support/core_ext/class/delegating_attributes'
 require 'active_support/core_ext/class/inheritable_attributes'
@@ -10,7 +11,6 @@ require 'active_support/core_ext/hash/indifferent_access'
 require 'active_support/core_ext/hash/slice'
 require 'active_support/core_ext/string/behavior'
 require 'active_support/core_ext/symbol'
-require 'active_support/core/time'
 
 module ActiveRecord #:nodoc:
   # Generic Active Record exception class.
diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index dab017770d..a1a140bc33 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -22,8 +22,15 @@
 #++
 
 module ActiveSupport
-  def self.load_all!
-    [Dependencies, Deprecation, Gzip, MessageVerifier, Multibyte, SecureRandom] + Core.load_all!
+  class << self
+    attr_accessor :load_all_hooks
+    def on_load_all(&hook) load_all_hooks << hook end
+    def load_all!; load_all_hooks.each { |hook| hook.call } end
+  end
+  self.load_all_hooks = []
+
+  on_load_all do
+    [Dependencies, Deprecation, Gzip, MessageVerifier, Multibyte, SecureRandom]
   end
 
   autoload :BacktraceCleaner, 'active_support/backtrace_cleaner'
diff --git a/activesupport/lib/active_support/all.rb b/activesupport/lib/active_support/all.rb
new file mode 100644
index 0000000000..f537818300
--- /dev/null
+++ b/activesupport/lib/active_support/all.rb
@@ -0,0 +1,3 @@
+require 'active_support'
+require 'active_support/time'
+require 'active_support/core_ext'
diff --git a/activesupport/lib/active_support/core.rb b/activesupport/lib/active_support/core.rb
deleted file mode 100644
index ad8db94941..0000000000
--- a/activesupport/lib/active_support/core.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-module ActiveSupport
-  module Core
-    def self.load_all!
-      [TimeWithZone]
-    end
-  end
-end
diff --git a/activesupport/lib/active_support/core/all.rb b/activesupport/lib/active_support/core/all.rb
deleted file mode 100644
index 55e8b4cfac..0000000000
--- a/activesupport/lib/active_support/core/all.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-require 'active_support/core_ext'
-require 'active_support/core'
-Dir["#{File.dirname(__FILE__)}/*.rb"].sort.each do |path|
-  require "active_support/core/#{File.basename(path, '.rb')}"
-end
diff --git a/activesupport/lib/active_support/core/time.rb b/activesupport/lib/active_support/core/time.rb
deleted file mode 100644
index 43e13b5e58..0000000000
--- a/activesupport/lib/active_support/core/time.rb
+++ /dev/null
@@ -1,4 +0,0 @@
-require 'active_support/core/time/autoload'
-require 'active_support/core_ext/time'
-require 'active_support/core_ext/date'
-require 'active_support/core_ext/date_time'
diff --git a/activesupport/lib/active_support/core_ext/hash/conversions.rb b/activesupport/lib/active_support/core_ext/hash/conversions.rb
index fe1f79050c..2a34874d08 100644
--- a/activesupport/lib/active_support/core_ext/hash/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/hash/conversions.rb
@@ -1,8 +1,7 @@
-require 'date'
+require 'active_support/time'
 require 'active_support/core_ext/object/conversions'
 require 'active_support/core_ext/array/conversions'
 require 'active_support/core_ext/hash/reverse_merge'
-require 'active_support/core/time'
 
 class Hash
   # This module exists to decorate files deserialized using Hash.from_xml with
diff --git a/activesupport/lib/active_support/time.rb b/activesupport/lib/active_support/time.rb
new file mode 100644
index 0000000000..d36a683601
--- /dev/null
+++ b/activesupport/lib/active_support/time.rb
@@ -0,0 +1,14 @@
+require 'active_support'
+require 'active_support/core_ext/time'
+require 'active_support/core_ext/date'
+require 'active_support/core_ext/date_time'
+
+module ActiveSupport
+  autoload :Duration, 'active_support/duration'
+  autoload :TimeWithZone, 'active_support/time_with_zone'
+  autoload :TimeZone, 'active_support/values/time_zone'
+
+  on_load_all do
+    [Duration, TimeWithZone, TimeZone]
+  end
+end
diff --git a/activesupport/lib/active_support/core/time/autoload.rb b/activesupport/lib/active_support/time/autoload.rb
similarity index 100%
rename from activesupport/lib/active_support/core/time/autoload.rb
rename to activesupport/lib/active_support/time/autoload.rb
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index 30d4152729..6f16621ae5 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -1,5 +1,5 @@
 require 'abstract_unit'
-require 'active_support/core/time'
+require 'active_support/time'
 
 class DurationTest < ActiveSupport::TestCase
   def test_inspect
diff --git a/activesupport/test/core_ext/numeric_ext_test.rb b/activesupport/test/core_ext/numeric_ext_test.rb
index 74b086fa9c..992ec60302 100644
--- a/activesupport/test/core_ext/numeric_ext_test.rb
+++ b/activesupport/test/core_ext/numeric_ext_test.rb
@@ -1,7 +1,7 @@
 require 'abstract_unit'
+require 'active_support/time'
 require 'active_support/core_ext/numeric'
 require 'active_support/core_ext/integer'
-require 'active_support/core/time'
 
 class NumericExtTimeAndDateTimeTest < Test::Unit::TestCase
   def setup
diff --git a/activesupport/test/core_ext/object_and_class_ext_test.rb b/activesupport/test/core_ext/object_and_class_ext_test.rb
index 8869b053e6..f0121b862d 100644
--- a/activesupport/test/core_ext/object_and_class_ext_test.rb
+++ b/activesupport/test/core_ext/object_and_class_ext_test.rb
@@ -1,7 +1,7 @@
 require 'abstract_unit'
+require 'active_support/time'
 require 'active_support/core_ext/object'
 require 'active_support/core_ext/class/removal'
-require 'active_support/core/time'
 
 class ClassA; end
 class ClassB < ClassA; end
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index e265423f06..1c2d0fbce4 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -1,5 +1,5 @@
 require 'abstract_unit'
-require 'active_support/core/time'
+require 'active_support/time'
 
 class TimeExtCalculationsTest < Test::Unit::TestCase
   def test_seconds_since_midnight
diff --git a/activesupport/test/i18n_test.rb b/activesupport/test/i18n_test.rb
index 2a08abfb3e..9868f1e87d 100644
--- a/activesupport/test/i18n_test.rb
+++ b/activesupport/test/i18n_test.rb
@@ -1,5 +1,5 @@
 require 'abstract_unit'
-require 'active_support/core/time'
+require 'active_support/time'
 require 'active_support/core_ext/array/conversions'
 
 class I18nTest < Test::Unit::TestCase
diff --git a/activesupport/test/time_zone_test.rb b/activesupport/test/time_zone_test.rb
index 87d6ccc30d..99c4310854 100644
--- a/activesupport/test/time_zone_test.rb
+++ b/activesupport/test/time_zone_test.rb
@@ -1,5 +1,5 @@
 require 'abstract_unit'
-require 'active_support/core/time'
+require 'active_support/time'
 
 class TimeZoneTest < Test::Unit::TestCase
   def test_utc_to_local
diff --git a/railties/lib/console_app.rb b/railties/lib/console_app.rb
index 42bf50e01e..75e6f11ea3 100644
--- a/railties/lib/console_app.rb
+++ b/railties/lib/console_app.rb
@@ -1,5 +1,4 @@
-require 'active_support'
-require 'active_support/core/all'
+require 'active_support/all'
 require 'active_support/test_case'
 require 'action_controller'
 
diff --git a/railties/lib/initializer.rb b/railties/lib/initializer.rb
index 4c6de48a65..3c0d5940ea 100644
--- a/railties/lib/initializer.rb
+++ b/railties/lib/initializer.rb
@@ -263,9 +263,8 @@ module Rails
     # list. By default, all frameworks (Active Record, Active Support,
     # Action Pack, Action Mailer, and Active Resource) are loaded.
     def require_frameworks
-      require 'active_support'
+      require 'active_support/all'
       configuration.frameworks.each { |framework| require(framework.to_s) }
-      require 'active_support/core/all'
     rescue LoadError => e
       # Re-raise as RuntimeError because Mongrel would swallow LoadError.
       raise e.to_s
diff --git a/railties/lib/rails_generator.rb b/railties/lib/rails_generator.rb
index 201a9e0f91..85400932dd 100644
--- a/railties/lib/rails_generator.rb
+++ b/railties/lib/rails_generator.rb
@@ -21,16 +21,9 @@
 # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #++
 
-begin
-  require 'active_support'
-rescue LoadError
-  activesupport_path = "#{File.dirname(__FILE__)}/../../activesupport/lib"
-  if File.directory?(activesupport_path)
-    $:.unshift activesupport_path
-    require 'active_support'
-  end
-end
-require 'active_support/core/all'
+activesupport_path = "#{File.dirname(__FILE__)}/../../activesupport/lib"
+$:.unshift(activesupport_path) if File.directory?(activesupport_path)
+require 'active_support/all'
 
 $:.unshift(File.dirname(__FILE__))
 require 'rails_generator/base'
diff --git a/railties/lib/tasks/misc.rake b/railties/lib/tasks/misc.rake
index a2c338aa5b..fb2fc31dc1 100644
--- a/railties/lib/tasks/misc.rake
+++ b/railties/lib/tasks/misc.rake
@@ -31,7 +31,7 @@ namespace :time do
     desc 'Displays names of time zones recognized by the Rails TimeZone class with the same offset as the system local time'
     task :local do
       require 'active_support'
-      require 'active_support/core/time'
+      require 'active_support/time'
       jan_offset = Time.now.beginning_of_year.utc_offset
       jul_offset = Time.now.beginning_of_year.change(:month => 7).utc_offset
       offset = jan_offset < jul_offset ? jan_offset : jul_offset
@@ -41,7 +41,7 @@ namespace :time do
     # to find UTC -06:00 zones, OFFSET can be set to either -6, -6:00 or 21600
     def build_time_zone_list(method, offset = ENV['OFFSET'])
       require 'active_support'
-      require 'active_support/core/time'
+      require 'active_support/time'
       if offset
         offset = if offset.to_s.match(/(\+|-)?(\d+):(\d+)/)
           sign = $1 == '-' ? -1 : 1