docs: def get_datetime_interval(timestamp, diff, offset=0):
      """
      Returns datetime interval from timestamp backward in the past,
      computed using the milliseconds difference passed as argument.
      The final datetime is corrected with an optional offset.
      """
      fin_datetime = datetime.datetime.fromtimestamp(timestamp + offset)
      ini_datetime = datetime.datetime.fromtimestamp(timestamp - diff)
      return ini_datetime, fin_datetime