A new feature in feedland + feedlanddatabase versions 0.7.15 + 0.8.8.
Two new settings -- config.flDeleteOldItems, default false and config.ctDaysToKeep, default 365.
If enabled when FeedLand runs its nightly tasks it will delete all items older than ctDaysToKeep..
See worknotes for more info.
Unless you're helping test FeedLand, I recommend waiting a bit and let us burn this in our the main servers. It's running now on feedland.org and feedland.social. If all goes well we'll install it on feedland.com shortly.