You can find this and lots of other information in the sidebar by going to "Visitors" > "Visitor Trending." Under Visitor Trending you can go into subcategories to see your unique visitors, how much time visitors spend on your site, and pageviews. It's under the "Visits" tab that you'll be able to see when people have stopped at your shop.
The default graph for this displays visits according to day. You'll have to click on the small clock icon to display by time.
I also think it's best to expand the date range to get a more accurate result. You can see in the first graph below that there is a slight spike during the 7:00 hour. This is because (thankfully) I was featured on the front page at this hour during the last month. On the right the graph shows the time of visits to my Etsy shop over the course of three months and what is more "typical" for my shop.
Now what can you do with this information? The primary way I use this information is to determine when to list items. The highest traffic in my shop is from 10am to 4pm and again from 9pm to 11pm. I've chosen to ignore the 7am and 8am hours because I know of traffic from the front page at that time that likely skewed results. I'll list during these peak hours and avoid listing during early morning and dinnertime. For some, this might also be an affirmation to keep blogging during those times or promoting on Facebook. If one of my goals was to increase my international views, however, I might choose to list during those early morning hours to increase traffic. Having the information is the first step. After that you can learn to use it to work with your strengths, weaknesses, and your goals.