diff --git a/app/helpers/date_time_helper.rb b/app/helpers/date_time_helper.rb
index 8400fa865..a9c10e712 100644
--- a/app/helpers/date_time_helper.rb
+++ b/app/helpers/date_time_helper.rb
@@ -20,6 +20,7 @@ def length_timestamp(length)
   # * +String+ -> formated datetime object
   def format_datetime(obj)
     return unless obj
+    obj = DateTime.parse(obj) unless ob.respond_to?(:strftime)
 
     obj.strftime('%Y-%m-%d %H:%M')
   end