The steps for installation are:
Upload plugin-name.php to the /wp-content/plugins/ directory
Activate the plugin through the 'Plugins' menu in WordPress
Go to Settings > Writing and choose min/max interval between posts
Publish posts in rapid succession
After completing those steps and setting the min to 7 days, max to 14 days, I posted 5 posts in rapid succession over the course of 15 min. each of these 5 posts was immediately published to the site. What am I doing wrong?