Merge commit '3a2a15c6ea4d4603469861ed9be09da12a122e45' into glitch-soc/merge-upstream

Conflicts:
- `app/views/settings/preferences/appearance/show.html.haml`:
  Conflict because glitch-soc does not have a theme selector here.

app/services/app_sign_up_service.rb

@@ -35,7 +35,7 @@ class AppSignUpService < BaseService
   end
 
   def user_params
-    @params.slice(:email, :password, :agreement, :locale)
+    @params.slice(:email, :password, :agreement, :locale, :time_zone)
   end
 
   def account_params