WP-Cron ist not a fully fledged cron implementation or something. It’s actually rather simple. On every page load, a list of scheduled tasks is checked to see what needs to be run. Any tasks scheduled to be run will be run during that page load. By default, tasks can be scheduled to be run hourly, … Read more
You can specify when the first execution will be performed using the first parameter of the wp_schedule_event function. So, according to your code, the first execution will be immediately and the following one will be in 7,884,000 seconds (which is around 91.25 days). I do not recommend this approach because the WP cron scheduled periods … Read more
It’s not possible with just WordPress to schedule code to run in the background at a specific time. WordPress, like most (if not all) PHP web applications, only actually runs in response to a URL being accessed, and a request being made to the server. For a scheduled event to run at a certain time, … Read more
Although both of your options (that is, using transients or using a cron job) are viable, I’m a fan of using transients unless the dataset is exceptionally large or if there is some need to automate the process. Without seeing much of your current code, it’s difficult to give a working example. Nonetheless, if you … Read more
The Problem: When wp-cron.php is called, it includes only: require_once( dirname( __FILE__ ) . ‘/wp-load.php’ ); so the problem you are facing is that wpmu_delete_blog() is undefined when you call it from your remove_blogs_daily() function. Possible Solution: You therefore need to add this line: require_once( ABSPATH . ‘wp-admin/includes/admin.php’ ); into your code to fix that. … Read more
When you run things on the CLI (which is pretty much where Cronjob and runwhen jobs are running), then you don’t have access to some things like some server or request variable contents, etc. What you need to do is fire up WP Core. Else you won’t have access to the full WP API. One … Read more
If you want a quick programmatic way of looping through everything you have in the cron row inside wp_options and you have access to the site’s database directly (either in a local development environment or on a webhost), you can run something like this via the command line: mysql $YOUR_DB_NAME -e “SELECT option_value FROM wp_options … Read more
When you register a scheduled event for WordPress’ cron, the 3rd argument is a hook name: wp_schedule_event( time(), ‘hourly’, ‘my_hourly_event’ ); And you add a function to run on this hook with add_action(): add_action( ‘my_hourly_event’, ‘do_this_hourly’ ); This will cause do_this_hourly() to run whenever the scheduled event runs. This works because when the scheduled time … Read more
Since wp_mail is pluggable, we can selectively override it. I run the following code in my general functionality plugin: /** * Email Async. * * We override the wp_mail function for all non-cron requests with a function that simply * captures the arguments and schedules a cron event to send the email. */ if ( … Read more
wp_cron operates on intervals and there is no interval that will hit exactly the first day and the 15th of every month. You could run your wp-cron job every day and check the date, similar to this but with a simple callback like: cron_callback_wpse_113675() { $date = date(‘d’); if (’01’ == $date || ’15’ == … Read more