I've been doing social media postings for a long time but i have not really specifically figured out the "best" schedule to post. And, I have not really bothered experimenting or researching about it. So it's really more of gut-feel.
So how I do it is that I just based it on my behavior on facebook. So morning, I either position it before a runner go for a run, or maybe when he's on commute or upon arriving in his office. Then, next will be around lunch time, then on the way home. If I want to post more, I will add posts during their afternoon break, and on the way to sleep.
I "will" be working on a project with Third Team Media, and so I read up on their lessons / references. And, I came across a few "theories" regarding how to schedule your facebook / social media posts.
Here are some of the social media content scheduling (they kind of vary):