def calculate_stage_part_visible_time_range(stage_part):
    """
    Calculate the visible time range of the stage treatment.

    Args:
        stage_part: The stage part identifying the stage treatment of interest.

    Returns:
        A `tuple` identifying the start and stop of the stage treatment.
    """
    return stage_part.StartTime.AddHours(-1), stage_part.StopTime.AddHours(1)