1 files changed, 45 insertions, 10 deletions
diff --git a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
index b7fe079ef5..f9beb43e4b 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -1,21 +1,27 @@
 module ActiveRecord
   module AttributeMethods
     module TimeZoneConversion
-      class TimeZoneConverter < SimpleDelegator # :nodoc:
-        include Type::Decorator
-
-        def type_cast_from_database(value)
+      class TimeZoneConverter < DelegateClass(Type::Value) # :nodoc:
+        def deserialize(value)
           convert_time_to_time_zone(super)
         end
 
-        def type_cast_from_user(value)
+        def cast(value)
           if value.is_a?(Array)
-            value.map { |v| type_cast_from_user(v) }
+            value.map { |v| cast(v) }
+          elsif value.is_a?(Hash)
+            set_time_zone_without_conversion(super)
           elsif value.respond_to?(:in_time_zone)
-            value.in_time_zone
+            begin
+              user_input_in_time_zone(value) || super
+            rescue ArgumentError
+              nil
+            end
           end
         end
 
+        private
+
         def convert_time_to_time_zone(value)
           if value.is_a?(Array)
             value.map { |v| convert_time_to_time_zone(v) }
@@ -25,6 +31,10 @@ module ActiveRecord
             value
           end
         end
+
+        def set_time_zone_without_conversion(value)
+          ::Time.zone.local_to_utc(value).in_time_zone
+        end
       end
 
       extend ActiveSupport::Concern
@@ -35,6 +45,9 @@ module ActiveRecord
 
         class_attribute :skip_time_zone_conversion_for_attributes, instance_writer: false
         self.skip_time_zone_conversion_for_attributes = []
+
+        class_attribute :time_zone_aware_types, instance_writer: false
+        self.time_zone_aware_types = [:datetime, :not_explicitly_configured]
       end
 
       module ClassMethods
@@ -55,9 +68,31 @@ module ActiveRecord
         end
 
         def create_time_zone_conversion_attribute?(name, cast_type)
-          time_zone_aware_attributes &&
-            !self.skip_time_zone_conversion_for_attributes.include?(name.to_sym) &&
-            (:datetime == cast_type.type)
+          enabled_for_column = time_zone_aware_attributes &&
+            !self.skip_time_zone_conversion_for_attributes.include?(name.to_sym)
+          result = enabled_for_column &&
+            time_zone_aware_types.include?(cast_type.type)
+
+          if enabled_for_column &&
+            !result &&
+            cast_type.type == :time &&
+            time_zone_aware_types.include?(:not_explicitly_configured)
+            ActiveSupport::Deprecation.warn(<<-MESSAGE)
+              Time columns will become time zone aware in Rails 5.1. This
+              still causes `String`s to be parsed as if they were in `Time.zone`,
+              and `Time`s to be converted to `Time.zone`.
+
+              To keep the old behavior, you must add the following to your initializer:
+
+                  config.active_record.time_zone_aware_types = [:datetime]
+
+              To silence this deprecation warning, add the following:
+
+                  config.active_record.time_zone_aware_types << :time
+            MESSAGE
+          end
+
+          result
         end
       end
     end