This is a great question and the answers are awesome. I publish like pagesvoice suggests mostly. Yet, I have friends worldwide too. Some I have a desire to be the first to read at times, so I consider their world clock.
Audience is a 'key' I guess I am saying. I believe there is the audience and the readership. So, I tend to publish for the audience first. How the audience is defined for each article comes into play. I know some of my hubber friends are in like Ohio, work nights, and have kids to get to school. So, about what time would that audience be sitting down with a cup of coffee or tea and visiting hubpages visits my mind.
Others, I know live a hectic pace with business or work, teachers and who knows. I haven't a cell or smart phone, yet they do. So, when to alert them of a que becomes some thought too.
In a round about way the friends you make along the way are going to be the best advertisers for you. Their willingness to share along the way will help you out as the phenomena of reciprocity comes into play and a little faith in the cosmos.
Google will help you along the way especially with practice adding up to experience multiplied by friends and family regarding readership, time does tell in most cases. Yet, if you wrote for a specific audience, then take three deep breaths, give thought of that audience, then plan the next move. Everything else is just icing and jirel you are the baker of that cake.