wp_schedule_event()

wp_schedule_event( int $timestamp, string $recurrence, string $hook, array $args = array(), bool $wp_error = false ): bool|WP_Error

function wp_schedule_event( $timestamp, $recurrence, $hook, $args = array(), $wp_error = false ) {
	// Make sure timestamp is a positive integer.
	if ( ! is_numeric( $timestamp ) || $timestamp <= 0 ) {
		if ( $wp_error ) {
			return new WP_Error(
				'invalid_timestamp',
				__( 'Event timestamp must be a valid Unix timestamp.' )
			);
		}

		return false;
	}

	$schedules = wp_get_schedules();

	if ( ! isset( $schedules[ $recurrence ] ) ) {
		if ( $wp_error ) {
			return new WP_Error(
				'invalid_schedule',
				__( 'Event schedule does not exist.' )
			);
		}

		return false;
	}

	$event = (object) array(
		'hook'      => $hook,
		'timestamp' => $timestamp,
		'schedule'  => $recurrence,
		'args'      => $args,
		'interval'  => $schedules[ $recurrence ]['interval'],
	);

	/** This filter is documented in wp-includes/cron.php */
	$pre = apply_filters( 'pre_schedule_event', null, $event, $wp_error );

	if ( null !== $pre ) {
		if ( $wp_error && false === $pre ) {
			return new WP_Error(
				'pre_schedule_event_false',
				__( 'A plugin prevented the event from being scheduled.' )
			);
		}

		if ( ! $wp_error && is_wp_error( $pre ) ) {
			return false;
		}

		return $pre;
	}

	/** This filter is documented in wp-includes/cron.php */
	$event = apply_filters( 'schedule_event', $event );

	// A plugin disallowed this event.
	if ( ! $event ) {
		if ( $wp_error ) {
			return new WP_Error(
				'schedule_event_false',
				__( 'A plugin disallowed this event.' )
			);
		}

		return false;
	}

	$key = md5( serialize( $event->args ) );

	$crons = _get_cron_array();

	$crons[ $event->timestamp ][ $event->hook ][ $key ] = array(
		'schedule' => $event->schedule,
		'args'     => $event->args,
		'interval' => $event->interval,
	);
	uksort( $crons, 'strnatcasecmp' );

	return _set_cron_array( $crons, $wp_error );
}