If you want to look within a specific project and state, you can use the Find Version tool in Workbench to search for files checked in by a specific user and/or created during a selected time frame.
If you want to search across many projects, you will need to create your report using SQL.
Here is an example of a query that would work:
SELECT HARENVIRONMENT.ENVIRONMENTNAME,
HARSTATE.STATENAME,
HARPACKAGE.PACKAGENAME,
HARPATHFULLNAME.PATHFULLNAME,
HARITEMNAME.ITEMNAME,
HARVERSIONS.MAPPEDVERSION,
HARVERSIONS.VERSIONSTATUS,
HARUSER.USERNAME,
HARVERSIONS.CREATIONTIME
FROM HARENVIRONMENT
INNER JOIN HARSTATE
ON HARENVIRONMENT.ENVOBJID = HARSTATE.ENVOBJID
INNER JOIN HARPACKAGE ON HARPACKAGE.STATEOBJID = HARSTATE.STATEOBJID
INNER JOIN HARVERSIONS ON HARPACKAGE.PACKAGEOBJID = HARVERSIONS.PACKAGEOBJID
INNER JOIN HARPATHFULLNAME ON HARVERSIONS.PATHVERSIONID = HARPATHFULLNAME.VERSIONOBJID
INNER JOIN HARITEMNAME ON HARITEMNAME.NAMEOBJID = HARVERSIONS.ITEMNAMEID
INNER JOIN HARUSER ON HARVERSIONS.CREATORID = HARUSER.USROBJID
WHERE LENGTH(HARENVIRONMENT.ENVIRONMENTNAME) > 1
AND HARPACKAGE.PACKAGENAME != 'BASE'
AND HARUSER.USERNAME = 'harvest'
AND HARVERSIONS.CREATIONTIME BETWEEN '06-SEP-17' AND '29-SEP-2017'
Let me know if this is what you needed.