diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index bee66de..8f2765e 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -475,6 +475,14 @@ module ApplicationHelper
     end
   end
 
+  def show_period(date1, date2 = nil)
+    if (date1 == date2) || (date2.nil?)
+      show_date(date1)
+    else
+      _('from %s to %s') % [show_date(date1), show_date(date2)]
+    end
+  end
+
   def gravatar_url_for(email, options = {})
     # Ta dando erro de roteamento
     url_for( { :gravatar_id => Digest::MD5.hexdigest(email),
diff --git a/test/unit/application_helper_test.rb b/test/unit/application_helper_test.rb
index 28e25ab..0b79336 100644
--- a/test/unit/application_helper_test.rb
+++ b/test/unit/application_helper_test.rb
@@ -100,6 +100,28 @@ class ApplicationHelperTest < Test::Unit::TestCase
     assert_not_nil theme_javascript
   end
 
+  should 'generate period with two dates' do
+    date1 = mock
+    expects(:show_date).with(date1).returns('XXX')
+    date2 = mock
+    expects(:show_date).with(date2).returns('YYY')
+    expects(:_).with('from %s to %s').returns('from %s to %s')
+    assert_equal 'from XXX to YYY', show_period(date1, date2)
+  end
+
+  should 'generate period with two equal dates' do
+    date1 = mock
+    expects(:show_date).with(date1).returns('XXX')
+    assert_equal 'XXX', show_period(date1, date1)
+  end
+
+  should 'generate period with one date only' do
+    date1 = mock
+    expects(:show_date).with(date1).returns('XXX')
+    assert_equal 'XXX', show_period(date1)
+  end
+
+
   protected
 
   def content_tag(tag, content, options)
--
libgit2 0.21.2