3 files changed, 27 insertions, 10 deletions
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index e29dc636df..8b0b7c8d70 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,4 +1,4 @@
-*   Make `Time.at_with_coercion` retain the second fraction and offset from UTC.
+*   Make `Time.at_with_coercion` retain the second fraction and return local time.
 
     Fixes #11350
 
diff --git a/activesupport/lib/active_support/core_ext/time/calculations.rb b/activesupport/lib/active_support/core_ext/time/calculations.rb
index 20e7e0b303..c739cce223 100644
--- a/activesupport/lib/active_support/core_ext/time/calculations.rb
+++ b/activesupport/lib/active_support/core_ext/time/calculations.rb
@@ -39,7 +39,7 @@ class Time
       time_or_number = args.first
 
       if time_or_number.is_a?(ActiveSupport::TimeWithZone) || time_or_number.is_a?(DateTime)
-        at_without_coercion(time_or_number.to_f).getlocal(time_or_number.utc_offset)
+        at_without_coercion(time_or_number.to_f).getlocal
       else
         at_without_coercion(time_or_number)
       end
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index 63fddd0cfd..8741f033b5 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -700,9 +700,18 @@ class TimeExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  def test_at_with_datetime_maintains_offset
+  def test_at_with_datetime_returns_local_time
     with_env_tz 'US/Eastern' do
-      assert_equal 3600, Time.at(DateTime.civil(2000, 1, 1, 0, 0, 0, '+1')).utc_offset
+      dt = DateTime.civil(2000, 1, 1, 0, 0, 0, '+0')
+      assert_equal Time.local(1999, 12, 31, 19, 0, 0), Time.at(dt)
+      assert_equal 'EST', Time.at(dt).zone
+      assert_equal(-18000, Time.at(dt).utc_offset)
+
+      # Daylight savings
+      dt = DateTime.civil(2000, 7, 1, 1, 0, 0, '+1')
+      assert_equal Time.local(2000, 6, 30, 20, 0, 0), Time.at(dt)
+      assert_equal 'EDT', Time.at(dt).zone
+      assert_equal(-14400, Time.at(dt).utc_offset)
     end
   end
 
@@ -717,10 +726,18 @@ class TimeExtCalculationsTest < ActiveSupport::TestCase
     end
   end
 
-  def test_at_with_time_with_zone_maintains_offset
+  def test_at_with_time_with_zone_returns_local_time
     with_env_tz 'US/Eastern' do
-      assert_equal 0, Time.at(ActiveSupport::TimeWithZone.new(Time.utc(2000, 1, 1, 0, 0, 0), ActiveSupport::TimeZone['London'])).utc_offset
-      assert_equal 3600, Time.at(ActiveSupport::TimeWithZone.new(Time.utc(2000, 7, 1, 0, 0, 0), ActiveSupport::TimeZone['London'])).utc_offset
+      twz = ActiveSupport::TimeWithZone.new(Time.utc(2000, 1, 1, 0, 0, 0), ActiveSupport::TimeZone['London'])
+      assert_equal Time.local(1999, 12, 31, 19, 0, 0), Time.at(twz)
+      assert_equal 'EST', Time.at(twz).zone
+      assert_equal(-18000, Time.at(twz).utc_offset)
+
+      # Daylight savings
+      twz = ActiveSupport::TimeWithZone.new(Time.utc(2000, 7, 1, 0, 0, 0), ActiveSupport::TimeZone['London'])
+      assert_equal Time.local(2000, 6, 30, 20, 0, 0), Time.at(twz)
+      assert_equal 'EDT', Time.at(twz).zone
+      assert_equal(-14400, Time.at(twz).utc_offset)
     end
   end
 
@@ -731,20 +748,20 @@ class TimeExtCalculationsTest < ActiveSupport::TestCase
   def test_at_with_utc_time
     with_env_tz 'US/Eastern' do
       assert_equal Time.utc(2000), Time.at(Time.utc(2000))
-      assert_equal 0, Time.at(Time.utc(2000)).utc_offset
       assert_equal 'UTC', Time.at(Time.utc(2000)).zone
+      assert_equal(0, Time.at(Time.utc(2000)).utc_offset)
     end
   end
 
   def test_at_with_local_time
     with_env_tz 'US/Eastern' do
       assert_equal Time.local(2000), Time.at(Time.local(2000))
-      assert_equal -18000, Time.at(Time.local(2000)).utc_offset
       assert_equal 'EST', Time.at(Time.local(2000)).zone
+      assert_equal(-18000, Time.at(Time.local(2000)).utc_offset)
 
       assert_equal Time.local(2000, 7, 1), Time.at(Time.local(2000, 7, 1))
-      assert_equal -14400, Time.at(Time.local(2000, 7, 1)).utc_offset
       assert_equal 'EDT', Time.at(Time.local(2000, 7, 1)).zone
+      assert_equal(-14400, Time.at(Time.local(2000, 7, 1)).utc_offset)
     end
   end