For a while now I've been maintaining a CogSci.SE facebook page (facebook-link). At the moment, every Monday at 20:00 CEST (UTC+2), i.e 18:00 GMT and 13:00 PDT (UTC-7), I post a question on the page. Unfortunately, after two months of work, the reach of these posts is not as good as I hoped for. Without further liking and sharing, we reach about 50 people. I believe this may be because of the time that I post the questions.
I chose for the current moment because I knew for sure that everybody would be awake at this moment. I believed that western Europe and the entire US would most likely be our best bet. However, this makes it difficult to time the post just right, because I don't know when people check their Facebook most often.
What would be a better moment for posting these questions?
In order to answer this questions we must determine on which area we will focus our attention. Where can we find the most audience, and at what time in day (morning, afternoon, evening) do we need to post the question?