The moment that a definite answer is formed for this particular question, is also the moment when it will stop being true. If, say, we determine that 18'00 UTC is the best time, then if everyone posts at that time there will be a flood of posts that will not be able to get properly evaluated and thus properly upvoted. Yet that will open a "gap" in other hours of the day where posting would be so slow that the moment something interesting is posted it will get all the attention.

So, in a way, while there definitely are hours where better rewards can be obtained (due to whale voter patterns), if this worked as an incentive for synchronized posting / bulk posting, it would have the opposite effect to what the author wants to achieve.

Hey there :) The best time to post is whenever you're ready. That will help Steemit be active every time and not at just one particular time :)

When to Publish / 8/16/2016 / bitcalm / https://steemit.com/programming/@bitcalm/when-is-the-best-time-to-publish-on-steemit / Statistical analysis of (whale) user activity concluding best value is posting is on a Monday at 18:00 UTC, or more generally, at the beginning of the week; worst time is 04:00 and 10:00 UTC.