在转换为UTC 0时区之前,Rails从何处获取时区?

# application.rb:
class Application < Rails::Application
   config.time_zone = 'Eastern Time (US & Canada)'
end
#model.rb
t = (Time.now-6.hours).beginning_of_day 
 #Use this method in your model with create and use the different 
 #timing 
 #and it look like -5 not -6 as mine :D