diff a/db/migrate/001_move_status_from_file_to_directory_name.rb b/db/migrate/001_move_status_from_file_to_directory_name.rb
--- a/db/migrate/001_move_status_from_file_to_directory_name.rb
+++ b/db/migrate/001_move_status_from_file_to_directory_name.rb
@@ -5,6 +5,9 @@
   status_file = Dir["#{dir}/build_status.*"].first
   next unless status_file
   status_info = File.basename(status_file).sub('build_status.', '')
+  new_dirname = "#{dir}-#{status_info}"
+  time_stamp = File.mtime(dir)
   rm status_file
-  mv dir, "#{dir}-#{status_info}"
+  mv dir, new_dirname
+  File.utime(time_stamp, time_stamp, new_dirname)
 end