Fixed a latent time zone bug in tests.

I created a new method accessible to all tests for forcing a user to the local time zone. The code was cribbed from Rails's rake tasks time:zones:local.

test/functional/todos_controller_test.rb

@@ -426,6 +426,7 @@ class TodosControllerTest < ActionController::TestCase
 
     # link todo_1 and recurring_todo_1
     recurring_todo_1 = RecurringTodo.find(1)
+    set_user_to_current_time_zone(recurring_todo_1.user)
     todo_1 = Todo.find_by_recurring_todo_id(1)
     today = Time.now.at_midnight
 

test/test_helper.rb

@@ -83,7 +83,22 @@ class ActiveSupport::TestCase
    end
   end
 
-  
+  def set_user_to_current_time_zone(user)
+    jan_offset = Time.now.beginning_of_year.utc_offset
+    jul_offset = Time.now.beginning_of_year.change(:month => 7).utc_offset
+    offset = jan_offset < jul_offset ? jan_offset : jul_offset
+    offset = if offset.to_s.match(/(\+|-)?(\d+):(\d+)/)
+      sign = $1 == '-' ? -1 : 1
+      hours, minutes = $2.to_f, $3.to_f
+      ((hours * 3600) + (minutes.to_f * 60)) * sign
+    elsif offset.to_f.abs <= 13
+      offset.to_f * 3600
+    else
+      offset.to_f
+    end
+    zone = ActiveSupport::TimeZone.all.find{|t| t.utc_offset == offset}
+    user.prefs.update_attribute(:time_zone, zone.name)
+  end
 end
 
 class ActionController::IntegrationTest