Reads sales from NetSuite (read only — nothing in NetSuite changes), then rebuilds the newest file Finance uploaded with NetSuite numbers from the month NetSuite starts and saves it as a new version. Earlier months stay exactly as Finance built them.
Each day takes about 15–30 seconds to read. The first sync reads every day since then (a few hours); you can close this page and press Sync again later — days already read are kept. Later syncs only read new days and re-read the last 7.