see below, a little clunky... relies on the fact that it had to be the
first time the SQL was ran.. and not aged out... but you never know,
you might get lucky. The best way is to take snapshots as Sybrand
recommended.

change date/times etc

SELECT
*
FROM
(
SELECT
SQL_TEXT,TO_DATE(FIRST_LOAD_TIME,'YYYY-MM-DD/HH24:MI:SS')
FIRST_LOAD_TIME
FROM
V$SQL
)
WHERE
FIRST_LOAD_TIME BETWEEN TO_DATE('2006-03-09 09:00:00','YYYY-MM-DD
HH24:MI:SS') AND TO_DATE('2006-03-09 11:00:00','YYYY-MM-DD HH24:MI:SS')