Source

File: wp-admin/includes/class-wp-site-health.php

public function maybe_create_scheduled_event() {
		if ( ! wp_next_scheduled( 'wp_site_health_scheduled_check' ) && ! wp_installing() ) {
			wp_schedule_event( time() + DAY_IN_SECONDS, 'weekly', 'wp_site_health_scheduled_check' );
		}
	}