Refresher Days triggers a reread of content after a predefined number of days based on the last read date. Refresher days of 365 would for a reread after 1 year. Refresher days of 0 forces the content to be constantly read.
If 0 Refresher Days is used to target mandatory content, the entry will always be visible in My Reads.
Content will be available for rereads after 80% of the read duration has lapsed. If the reread period was 100 days, the content would be available to reread after 80 days.