At the start of each year I simply move the previous year's entries into a new folder so I start each new year afresh (but keeping the balance from the previous year. It's just a drag and drop operation.
https://www.splasm.com/support/checkbookpro3/Use CheckBook Pro's Folders when you need to organize Entries, perhaps by calendar year, or move older Entries out of the way without completely removing them from your document.
1. Click the Entry button at the bottom of the document window.
2. If the Accounts sidebar is not visible to the right or left of the document window, click the sidebar button near the bottom left or right of the document window.
3. Go to the Accounts sidebar and click the name of the Account with the Entries you'd like to move to a Folder.
4. Go to the Accounts sidebar and click the triangle to the left of the selected Account's icon to reveal its Folders and Smart Folders.
5. Select the Entries you want to move. A single click selects a single Entry, Shift-clicking an Entry selects a contiguous group of Entries and Command-clicking an Entry adds it to the current selection.
6. Drag your selection to the appropriate Folder. If you need a new Folder, learn how to create a Folder.