3 files changed, 19 insertions, 0 deletions
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 5f81f45333..86e5b6f781 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,5 +1,9 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Added `ActiveSupport::TimeWithZone#to_r` for `Time#at` compatibility.
+
+    *stopdropandrew*
+
 *   `ActiveSupport::NumberHelper#number_to_human` returns the number unaltered when
     the given units hash does not contain the needed key, e.g. when the number provided
     is less than the largest key provided.
diff --git a/activesupport/lib/active_support/time_with_zone.rb b/activesupport/lib/active_support/time_with_zone.rb
index 0e6d12a186..98c866ac43 100644
--- a/activesupport/lib/active_support/time_with_zone.rb
+++ b/activesupport/lib/active_support/time_with_zone.rb
@@ -317,6 +317,10 @@ module ActiveSupport
     end
     alias_method :tv_sec, :to_i
 
+    def to_r
+      utc.to_r
+    end
+
     # Return an instance of Time in the system timezone.
     def to_time
       utc.to_time
diff --git a/activesupport/test/core_ext/time_with_zone_test.rb b/activesupport/test/core_ext/time_with_zone_test.rb
index 21fef88d79..0f5699fd63 100644
--- a/activesupport/test/core_ext/time_with_zone_test.rb
+++ b/activesupport/test/core_ext/time_with_zone_test.rb
@@ -326,6 +326,17 @@ class TimeWithZoneTest < ActiveSupport::TestCase
     assert_equal 946684800, twz.to_i
   end
 
+  def test_to_r
+    result = ActiveSupport::TimeWithZone.new(Time.utc(2000, 1, 1), ActiveSupport::TimeZone['Hawaii']).to_r
+    assert_equal Rational(946684800, 1), result
+    assert_kind_of Rational, result
+  end
+
+  def test_time_at
+    time = ActiveSupport::TimeWithZone.new(Time.utc(2000, 1, 1), ActiveSupport::TimeZone['Hawaii'])
+    assert_equal time, Time.at(time)
+  end
+
   def test_to_time
     with_env_tz 'US/Eastern' do
       assert_equal Time, @twz.to_time.class