diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 99f2707..f33f6c3 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -396,12 +396,20 @@ module ApplicationHelper
 
   # formats a date for displaying.
   def show_date(date)
-    date.strftime(_('%d %B %Y'))
+    if date
+      date.strftime(_('%d %B %Y'))
+    else
+      ''
+    end
   end
 
   # formats a datetime for displaying. 
   def show_time(time)
-    time.strftime(_('%d %B %Y, %H:%m'))
+    if time
+      time.strftime(_('%d %B %Y, %H:%m'))
+    else
+      ''
+    end
   end
 
 end
diff --git a/test/unit/application_helper_test.rb b/test/unit/application_helper_test.rb
index 26783af..11f12bd 100644
--- a/test/unit/application_helper_test.rb
+++ b/test/unit/application_helper_test.rb
@@ -35,6 +35,10 @@ class ApplicationHelperTest < Test::Unit::TestCase
     assert_equal 'translated date', show_date(date)
   end
 
+  should 'handle nil dates' do
+    assert_equal '', show_date(nil)
+  end
+
   should 'translate time' do
     time = mock
     expects(:_).with('%d %B %Y, %H:%m').returns('the time')
@@ -42,6 +46,10 @@ class ApplicationHelperTest < Test::Unit::TestCase
     assert_equal 'translated time', show_time(time)
   end
 
+  should 'handle nil time' do
+    assert_equal '', show_time(nil)
+  end
+
   protected
 
   def content_tag(tag, content, options)
--
libgit2 0.21.2