If you have a business Instagram account, the Insights include some great information about not just your own posts but your followers too. You can cycle through the each day of the week and see when your followers are most likely to be online.
If you want to see when users are most active at a particular business location, you can use our free location report at free.foundontack.com. We’ll look at up to 500 posts at the location and build a report about what’s popular and when people are posting. Check it out and let me know what you think!