Number of archived redo by day

SELECT TRUNC(first_time) AS day,
ROUND(SUM(blocks * block_size)/1024/1024/1024,2) size_gb
FROM v$archived_log
WHERE TRUNC(first_time) >= TRUNC(SYSDATE) – &1
GROUP BY TRUNC(first_time)
ORDER BY TRUNC(first_time);