I have been posting for 6 years now and always figured the best time post was between 9am and 1pm New York time.
I live in Sydney - so 11 hours away from UTC. I know from 593 investing posts that posting daytime, my time is always a poor vote result.
Your data shows exactly the quiet spells overlap fully with Australian day time. LeoFinance does have the ability to schedule posts BUT I have never been able to get one to work. I wake up in he morning to Broadcast error. Sucks.