ultimatemember/includes/core/class-cron.php

<?php
namespace um\core;

// Exit if accessed directly
if ( ! defined( 'ABSPATH' ) ) exit;

if ( ! class_exists( 'Cron' ) ) {
    class Cron {

        public function __construct() {
            add_filter( 'cron_schedules', array( $this, 'add_schedules'   ) );
            add_action( 'wp',             array( $this, 'schedule_Events' ) );
        }

        public function add_schedules( $schedules = array() ) {

            // Adds once weekly to the existing schedules.
            $schedules['weekly'] = array(
                'interval' => 604800,
                'display'  => __( 'Once Weekly', 'ultimate-member' )
            );

            return $schedules;
        }

        public function schedule_Events() {
            $this->weekly_events();
            $this->daily_events();
            $this->twicedaily_events();
            $this->hourly_events();
        }

        private function weekly_events() {
            if ( ! wp_next_scheduled( 'um_weekly_scheduled_events' ) ) {
                wp_schedule_event( current_time( 'timestamp' ), 'weekly', 'um_weekly_scheduled_events' );
            }
        }

        private function daily_events() {
            if ( ! wp_next_scheduled( 'um_daily_scheduled_events' ) ) {
                wp_schedule_event( current_time( 'timestamp' ), 'daily', 'um_daily_scheduled_events' );
            }
        }

        private function twicedaily_events() {
            if ( ! wp_next_scheduled( 'um_twicedaily_scheduled_events' ) ) {
                wp_schedule_event( current_time( 'timestamp' ), 'twicedaily', 'um_twicedaily_scheduled_events' );
            }
        }

        private function hourly_events() {
            if ( ! wp_next_scheduled( 'um_hourly_scheduled_events' ) ) {
                wp_schedule_event( current_time( 'timestamp' ), 'hourly', 'um_hourly_scheduled_events' );
            }
        }

    }
}