When promoting your self-published book, the social media tool Pinterest ought to play an important role in the marketing strategy. Knowing when to pin, however, can maximize your efforts.

According to a number of studies, the best time to pin is 2-4 p.m. weekdays and on Saturday mornings. This is particularly true for fashion and retail businesses, and one might extrapolate from that books, since they are retail products.

As the weekend approaches, more users tend to be on Pinterest. Peak use occurs at 3 p.m. Friday.

Of course, these times are relative. If your business is national, you need to pin over a longer spread of time than 2-4 p.m. in your time zone, or you’ll miss the peak times in other parts of the country. For example, if your business is based in Chicago (Central Time), you would aim messages for the East Coast (i.e. New York City, Philadelphia, Raleigh) at 1-3 p.m. Central Time and messages for the West Coast (i.e. Los Angeles, San Francisco, Seattle) at 4-6 p.m. Central Time.

If you have limited hours to spend promoting your book, consider cutting Facebook but keeping Pinterest. Studies show that more social media users engage with retailers and brands via Pinteret than Facebook (55% vs. 48%). Note, though, that Facebook has more users than Pinterest, so in terms of raw numbers, those percentages may be irrelevant.

The absolute worst time to pin are morning work hours. Though people are on Pinterest during this time, the number of users drops considerably compared to the earlier mentioned peak hours.