There is a form for one gruop of host have diferent type of blocs… ex: one gruop of host can have acces to youtube at the hour 16:00 -17:00 and the other group don´t have acces never y the same day
You can configure firewall objects (hosts, ip ranges…) and time conditions. Afterwards, you can create the desired firewall rules specifying a firewall object as source, selecting a service (youtube…) and a time condition.
Web content filter has a similar feature (Times, profiles).
a quick and dirty example…