WP-Cron is a plugin to support periodic execution of actions / plugins / stuff! From the readme:
WP-Cron provides a rudimentary support for scheduled exection of actions; a sort of “delayed action” processing for WordPress. It is nowhere near as robust as the actual UNIX cron facility, but should be good enough to “do stuff” on a fairly regular basis.
What with human beings, search engine spiders, and content aggregators, we can be fairly sure that even the most uninteresting (public) blog will be visited with some regularity. WP-Cron relies on this regularity to schedule the execution of three new plugin hooks. These hooks execute roughly once every fifteen minutes, every hour, or every day.
Included in the download are three example plugins to demonstrate how to use WP-Cron:
- wp-cron-dashboard: uses WP-Cron to update the data in your WordPress dashboard (roughly) every hour.
- wp-cron-reminder: sends out a generic reminder email to the blog admin (roughly) every 15 and 60 minutes. You can use this to prove to yourself that WP-Cron is working.
- wp-cron-future-pings: suppresses the default ping and trackback action when you post a new item dated in the future. Then (roughly) every 15 minutes the plugin checks to see if any future-dated posts are now visible to readers. If they are, the pings and trackbacks are sent! (note: wp-cron-future-pings requires WordPress 18.104.22.168 to work properly: see changeset 2604)
- wp-cron-mail: a plugin version of the
wp-mail.phpscript, written to use WP-Cron to support blog-by-email.
Follow developments of WP-Cron here!