Command line entry point for dcal.

def main():
    """Command line entry point for dcal."""

    if "--help" in sys.argv or "-h" in sys.argv or len(sys.argv) > 3:
        raise SystemExit(__doc__)

    try:
        discordian_calendar(*sys.argv[1:])
    except ValueError as error:
        raise SystemExit("Error: {}".format("\n".join(error.args)))