current_user_set_time_zone.rb

# Here's an example of how you might set <tt>Time.zone</tt> on a per request basis and reset it when the request is done.
# <tt>current_user.time_zone</tt> just needs to return a string identifying the user's preferred time zone:
#
  class ApplicationController < ActionController::Base
    around_action :set_time_zone

    def set_time_zone
      if logged_in?
        Time.use_zone(current_user.time_zone) { yield }
      else
        yield
      end
    end
  end