Intuit notifies ChronoBooks about changes to your QuickBooks Online company. These notifications are typically sent about 5-10 minutes after changes are made. When ChronoBooks receives a notification, it goes to back up all recent changes. We also backdate those changes as to when they were made in QuickBooks Online.
As a fallback for the event that ChronoBooks stops receiving these notifications, we also poll for changes each hour and run daily scheduled backups.