--- original_migrate_from_mantis.rake	2015-01-11 09:20:11.000000000 +0000
+++ fix_migrate_from_mantis.rake	2015-02-02 15:53:38.548233600 +0000
@@ -345,7 +345,7 @@
 
         # Bug files
         bug.bug_files.each do |file|
-          a = Attachment.new :created_on => file.date_added
+          a = Attachment.new :created_on => Time.at(file.date_added)
           a.file = file
           a.author = User.first
           a.container = i