WP-Cron and scheduled events
WP-Cron is how WordPress runs tasks on a schedule: publishing a post you planned for next Monday, checking twice a day for updates, cleaning up old data, sending a newsletter, making a backup. Each planned task is a scheduled event: a point in time, the task to run, and, for recurring tasks, how often.
Why it matters
Section titled “Why it matters”A lot of what makes a site run happens in these tasks, out of sight. When they don’t run on time, scheduled posts are late, update checks don’t happen, backups are missing and temporary data piles up in the database.
WP-Cron doesn’t run on its own clock. It checks on every page load whether a task is due and starts it then. On a site with few visits, a task planned for 2 p.m. may run only when the next visitor arrives at 5 p.m. On a busy site, the checks happen constantly.
The list of scheduled events usually stays stable. When it keeps growing, a plugin is often adding events without removing old ones. WordPress keeps the whole list in a single setting that it loads on every request, so a long list adds weight everywhere.
What influences it
Section titled “What influences it”Cache: Visits that a page cache answers don’t start WordPress, so they don’t start WP-Cron either. On a well-cached site with little traffic, tasks can wait for hours.
WordPress: WordPress and most plugins schedule events of their own. Plugins that create a separate event for every item, or don’t remove their events when they’re deactivated, make the list grow. A task that fails or takes very long holds up the ones behind it.
Server: Instead of relying on visits, the server’s own scheduler can call WP-Cron at
fixed times. The site then sets DISABLE_WP_CRON in wp-config.php so that visits no longer start
it. Some hosting providers set this up by default.
In Permo
Section titled “In Permo”The Scheduled events card is in System info, tab Database, under Scheduled events. It shows the number of planned runs, with a line of the last 3 months below it, one count per day. Each combination of time, task and the details passed to it counts once, Permo’s own events included. The line shows whether the list stays put or keeps growing. The card gives context; Permo doesn’t rate it.
Below the card, Next runs lists the upcoming events: the task (its hook), who added it, when it runs next, how often it repeats and how many details it carries. Added by names a plugin or theme only when Permo can tell from the code that registered the task; otherwise it says Unknown.