process the main task

def main():
    """
    process the main task
    """
    args = get_args()
    args.start = date_parser.parse(args.start)
    args.end = date_parser.parse(args.end)
    args.step = timedelta(args.step)
    config = Config(args.config)

    times = [args.start + i * args.step for i in range(int((args.end - args.start) / args.step))]

    for i, time in enumerate(times):
        make_plot(time, config, args.step)