Implement user set time_zone

app/controllers/application_controller.rb

@@ -4,6 +4,7 @@ class ApplicationController < ActionController::Base
   helper_method :sort_direction, :sort_column
   before_filter :init_gon
   skip_before_filter  :verify_authenticity_token
+  around_filter :set_time_zone, :if => :current_user
 
   rescue_from CanCan::AccessDenied do |exception|
     unless current_user
@@ -275,4 +276,8 @@ def not_found
   helper_method :masquerading?
   helper_method :curr_user_course
   #helper_method :fb_liked?
+
+  def set_time_zone(&block)
+    Time.use_zone(current_user.try(:time_zone), &block)
+  end
 end

app/views/users/edit.html.erb

@@ -17,6 +17,7 @@
 
 <%= simple_form_for current_user, url: users_update_path, html: {class: "form-horizontal"} do |f| %>
     <%= f.input :name %>
+    <%= f.input :time_zone %>
     <%= f.input :use_uploaded_picture, as: :boolean %>
 
     <div class="control-group">