def make_timestamp_from_safe_file_name(file_name):
  """Helper: Returns a datestore timestamp string from a safe file name."""
  #r'^(\d\d\d\d)-(\d\d)-(\d\d)\s(\d\d):(\d\d):(\d\d)\.(\d*?)$'
  # ['backup', '2008', '08', '10', 'at', '14', '10', '08', '827815']
  g = file_name.split('_')
  timestamp = g[1] + '-' + g[2] + '-' + g[3] + ' ' + g[5] + ':' + g[6] + ':' + g[7] + '.' + g[8]
  return timestamp