1 files changed, 8 insertions, 2 deletions
diff --git a/activemodel/lib/active_model/type/helpers/time_value.rb b/activemodel/lib/active_model/type/helpers/time_value.rb
index c55bb1e136..0a0e58654b 100644
--- a/activemodel/lib/active_model/type/helpers/time_value.rb
+++ b/activemodel/lib/active_model/type/helpers/time_value.rb
@@ -1,3 +1,5 @@
+require "active_support/core_ext/time/zones"
+
 module ActiveModel
   module Type
     module Helpers
@@ -21,11 +23,15 @@ module ActiveModel
         end
 
         def is_utc?
-          ::Time.zone_default =~ 'UTC'
+          ::Time.zone_default.nil? || ::Time.zone_default =~ 'UTC'
         end
 
         def default_timezone
-          ::Time.zone_default
+          if is_utc?
+            :utc
+          else
+            :local
+          end
         end
 
         def type_cast_for_schema(value)