Currently, the ability to auto-save your transactions in QuickBooks is not available. However, you'd want to set QuickBooks so that it will not timeout for a maximum of 2 - 3 hrs. The time of inactivity is based on the time that you last save, or moved your mouse, clicked, or used your keyboard on any transaction form in QuickBooks.
Click the Gear icon.
Under Your Company, choose Account and Settings.
Go to the Advanced tab.
Click the pencil icon to edit the Other Preferences section.