Since you run a small business, I’ll assume that the audience you’re going to engage with consists of existing and potential customers as well as other people in your industry. So chances are, your audience will be a working audience. In this case you should think about which time of day they are most likely to consume your content.
Breakfast time, for example, is a very short window of attention in which people tend to skim through content searching for the most important news of the day relative to their interests.
Lunch time is another key slot. Many people spend part of their lunch break searching the web and this can be a productive time to engage your audience and get feedback. It also allows them time to “digest” your post over the course of the afternoon.
Evening time, or after work, is the final key slot. However, posting at night does attract a different type of mood and dynamic. In my case, for instance, I find that I am far more receptive to new content in the morning than I am at night. I also find that I tend to be more positive in the morning. Bear this in mind if you’re about to post a polemical piece!
For me, the ideal time to post new content is an hour or so before breakfast (6-7am) so that your readers have all day to pick up the content. Don’t forget that you can schedule your posts to be published at a specific time.