To repeat posts on a regular schedule, you need to use queues.
Set up a queue that publishes at the desired frequency, and load the correct number of posts in the queue.
For example, if the queue is set to publish once every 2 hours, and there are 36 posts in the queue, then each post will repeatedly be published once every 72 hours.
Remember to configure the queue to auto-recycle used posts back into the queue.