Today I've tried to write a Wordpress Cronjob. For testing purposes I wrote a function that sends me an email every hour, but it's not working. I've got a plugin called 'Core Control' which shows me all existing Cronjobs - mine is also listed there. There is also a button "Run now". If I press it, I get the test-mail, so the function itself is correct.

Here is the code for the Cronjob, it is placed inside the functions.php of my theme.

if( !wp_next_scheduled( 'check_cron' ) ) {  
   wp_schedule_event( time(), 'hourly', 'check_cron' );  

add_action( 'check_cron', 'sendit' );

function sendit() {  
    $address = "[email protected]";
    $sender = "Cron_Test";
    $sendermail = "[email protected]";
    $subject = "It works!";
    $text = "Yay, it is working!";

    mail($address, $subject, $text, "From: $sender <$sendermail>");    

There has to be something wrong with the action hook, but I have no idea what's wrong. Or do I need to place the code in some different file?

Some more Info: I now that mail(); does not work on localhost, that's why I created a test blog online. The folder is protected via .htaccess with a password, could that be an issue?

I also checked that my wp-config.php allows Cronjobs.

I also now that the site needs to be visited for the Cronjob to run.

  • Are you on WP 3.3? I have been having troube with wp-cron since the upgrade (posts with missed schedule), so maybe it is a general issue.
    – Raphael
    Commented Feb 11, 2012 at 19:34
  • Yes I am also on 3.3.!
    – Sven
    Commented Feb 11, 2012 at 19:57

1 Answer 1


Unfortunately the WordPress cron jobs are only triggered when your site is visited (see Codex):

The action will trigger when someone visits your WordPress site, if the scheduled time has passed.

I believe this to get around the fact that many on shared hosting aren't normally allowed to set up cron jobs (at least, not without contacting their host first).

  • Do you know if the cron job will run in the same request / process as the site visit which triggers it? i.e. will the site visitor who triggers the cron job experience a delay while the wp cron job runs?
    – codecowboy
    Commented Sep 28, 2013 at 7:15
  • It won't, no. It'll spawn a new one. If that's not allowed, I believe it triggers a http request of the page - that's the 'alternative wp cron', as a bit of hacky workaround for difficult hosts. Commented Sep 28, 2013 at 8:27

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