List of SQL Statements run on system by time and date

Hi

I am doing some performance investigation and would like to retrieve a list
of statements run by time and date in order to examine the statements run
at particular times of the day when CPU spikes.

I don't have performance tools or job watcher installed on the system but I
could get this done if it is the solution to my question.

I do have collection services running and I have extracted SQL Cache
snapshots to review the statements for particular periods.

I have some questions about the SQL Cache, for instance, if I run a cache
snapshot selecting statements that ran after a certain date or time, the
statistics for the statements included in that snapshot look to be for the
lifetime of that statement rather than for the just the period included in
the snapshot.

Is there a decent reference that anyone is aware of as to what is included
in the Cache snapshot and how to interpret/query the contents ?