Here 2 a bit different issues are described, but I suppose they are related each other.

(1)
Make sure "audit" table is empty;
Create 2 audit records (for example create 2 host groups), make sure they both are shown on Administration -> Audit when click "All" in time slider;
wait 3+ hours (or update clock for very first record, set now()-3h);
check the page again and notice that the very first record in not included anymore.
In debug section we can see condition "a.clock>'1447048842' AND a.clock<'1447064092'" while the very first record has 1447048842 clock.

A more specific detail - if you for example have already single different type audit record before creation 2 host groups and see those 2 records, then:

• when you select filter for Resource:Host_group and click Filter during 10 seconds after previous page loaded then you still will see those both records,
• but if you click Filter after 10 seconds - you will see that oldest record disappeared and you see only one record.

(2)
Make sure "events" table is empty;
Create 2 event trigger-based records, make sure they both are shown on Monitoring -> Events when click "All" in time slider AND when you press F5 to refresh the page;
wait 3+ hours (or update clock for very first record, set now()-3h);
check the page again and notice that when you refresh the page by pressing F5 then very first record in not included.
Although it's included when you click "All" in time period selection.
One more point is export to CSV - after the 3 hours when you try to export both visible events - the very first record will not be included.

Both subissues reproduced on Zabbix 2.4.7rc1-56357 and Zabbix 3.0.0alpha4-56321 and on ZBX-9236 dev branch (which I supposed is related) as it's not merged to trunk at this point.

Another similar issue ZBX-9497, but it includes pagination and it can be different issue, I cannot be sure here.
It could be retested after current fix, as my scenario in more simple to reproduce.

Another possible related issue is ZBX-9993, because:

• in "profiles" table for the "idx"=web.auditlogs.timeline.stime I can see that "stime"can be set to a far future like 20161108083713
• for events page I don't see such idx but in page URL I can see this: &period=13122&stime=20161108090700