I get where you're coming from, misselany.
Though, as what my colleague @Angelyn_T stated, the conversion tool is unable to convert a specific period only.
As a workaround, you'll want to start a QuickBooks company file from scratch, then enter the transactions manually. You can ask from Sage the Customer, Vendor, Items, and Chart of Accounts lists, and import them into the software using Excel files.
You can reach out to us again if you need more help. Have a great day!
