1 files changed, 29 insertions, 4 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 777f7ab4d7..e10024b2ec 100644
--- a/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
+++ b/activerecord/lib/active_record/attribute_methods/time_zone_conversion.rb
@@ -13,7 +13,7 @@ module ActiveRecord
             value.map { |v| type_cast_from_user(v) }
           elsif value.respond_to?(:in_time_zone)
             begin
-              value.in_time_zone || super
+              user_input_in_time_zone(value) || super
             rescue ArgumentError
               nil
             end
@@ -39,6 +39,9 @@ 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
@@ -59,9 +62,31 @@ 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
+              sill cause `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