def post_to_channel() -> None:
"""
Post to slack channel top 10 trending tweets scheduled every 3 hours.
:return: None
"""
t = threading.Timer(10800.0, post_to_channel)
t.daemon = True
t.start()
slack = Slack(HOOK_URL)
msg = get_top10_msg()
slack.post_to_channel(msg)
print(f'Posted - {time.strftime("%T", time.localtime())}')
