There is no "best time" to post. Once you are ready to post then that is as good of a time as any. "Publish or perish" as the saying goes.
If you really need a time backed by a logical reason my guess would be after 5 p.m. PST because that is when steemfollower.com resets its votes limit for the next 24 hours so curators can upvote another 10 posts.