Restrict the Available Time of Scheduler

[ziv.yip]

Hi all ;D,
Every night, our server will proceed a lot of  ETL jobs, and sometimes the ETL jobs are suspended by some user scheduled cognos reports. To prevent the suspension, we would like to restrict the available time of scheduled report, but we dont want to revoke the user's right to have schedule run. I would like to ask if we can change some configuration so that users cannot choose night time i.e.11:00pm for the scheduler/scheduled reports? Or can we use the "peak hour" setting to restrict the scheduled report run i.e. set the night time as peak hour and  available report connect during peak hour to zero  ? Hope you all can share some experience on similar case  ;D