InfiniteWP has a setting to fetch updates for your WordPress sites daily at 10 AM. For this feature to work, tick the check box on the screenshot below, and you should have configured the cronjob on your IWP-installed server or activated the Easycron API account. 

If you prefer a different time for the automatic update fetch, you can modify the config.php file in the IWP root folder by adding the below-specified constant.

define('CUSTOM_AUTO_UPDATE_FETCH_TIME', '10:00:00');