Hello,
I am sorry that I have not been in touch, work has been quite busy.
When the plugin is activated it tries to create a wordpress cron that runs every 15 minutes and checks for any posts that need to be emailed out. For some reason in very rare setups it creates the cron to start in 46 years. The page that says when the posts will be sent simply requests the date/time of when the cron is due to run next.
The reason I have not fixed this is because I have not been able to replicate the issue myself, I have asked a few people if they can give me access to their wordpress to debug the issue but they have never got back to me.
My “guess” is that another plugin is interfering with this plugin and causing the cron to change.
Richard