Wordpress: Schedule a hook to be triggered by at the specified interval.

Wordpress core have inbuilt tasks shedule functionality to run hooks at the specified interval. We can shedule custom events using wp_schedule_event() and wp_next_scheduled() hooks which will be triggered by WordPress at the specified interval.

Important Note: The action will trigger only when someone visits your WordPress site if the scheduled time has passed. So they are not accurate, If you want to schedule function to be executed at the specified time then you should use Linux cron jobs or other mechanism.

add_action('admin_init', 'devnodes_init');
function devnodes_init()
{
  if (!wp_next_scheduled('DEVNODES_DAILY_TASK')) {
    // sheduled to run at 6 AM IST daily = 00:30 in UTC
    wp_schedule_event(strtotime('00:30:00'), 'daily', 'DEVNODES_DAILY_TASK');
  }
}

add_action('DEVNODES_DAILY_TASK', 'devnodes_task_daily_hook');
function devnodes_task_daily_hook()
{
  //This function will run every day at scheduled time
  //Your code goes here...
}