Compute whether each customer bought again inside a window after the first purchase; for example, set N to 7 and see the one-week returns.
From an Excel order log, check whether each customer’s second purchase landed within N days of the first. Download sample and blank workbooks. Browser-local; no account.
Upload an Excel workbook with an identity and a date, set N days, then compute.
Download the template pack for a filled sample workbook and a header-only blank workbook. Map the required columns, compute in the browser, then export a result sheet. No signup.