{"content":"SheetJS xlsx 0.18: XLSX.utils.book_new() creates workbook. XLSX.utils.aoa_to_sheet(rows) from array-of-arrays where rows[0] = headers. XLSX.utils.book_append_sheet(wb, ws, sheetName). XLSX.write(wb, { type:'buffer', bookType:'xlsx' }) returns Buffer. Date cells: pass JS Date objects, xlsx serializes to Excel date serial. Cell formatting: ws[cellAddr].z = 'DD.MM.YYYY' for display format. German date format 'TT.MM.JJJJ' in the data = string, not Date object, so just write as string. Numeric km: write as number, no unit.","source":"web","provider":"websearch","confidence":"LOW","fetched_at":"2026-06-26T12:30:47.031Z","ttl":86400000,"kind":"docs"}