def mult_time(clock_wall_time, mult):
    """ Multiply times in hh:mm:ss by some multiplier.

    Arguments
    ---------
    clock_wall_time: str
        Time delta in hh:mm:ss format.
    mult
        Multiplier for the time.

    Returns
    -------
    str:
        Time delta multiplied by the multiplier in hh:mm:ss format.
    """
    hhmmss = clock_wall_time.split(":")
    hhmmss.reverse()

    new_ss = (int(hhmmss[0])*mult)
    new_mm = new_ss // 60
    new_ss %= 60
    new_mm += (int(hhmmss[1])*mult)
    new_hh = new_mm // 60
    new_mm %= 60
    new_hh += (int(hhmmss[2])*mult)

    new_hhmmss = "{hh:02d}:{mm:02d}:{ss:02d}".format(hh=new_hh, mm=new_mm,
                                                     ss=new_ss)
    return new_hhmmss