With these holidays have tiny break (I.e. Having the weekend off is a smart idea). You guys are about to ENTER(pun intended) the most hectic part of year 12. During this weekend try and forget ENTER and study scores. With studying try and be as creative as you can with your study methods. Attend any seminars set by your teachers and after these holidays you should be tackling as many exams as possible.
With studying instead of setting a time limit, make reasonable promises fo yourself. E.g. Physics: Today my goal is to work out what my weaknesses are in magnetism? what does a commutator do? if I were asked about magnetic flux could I give a reasonable answer?
Spreading your time out is a great idea! If you have studied for over 1 hour you'll find you can't recall what you studied.
So these holidays make sure you get a fair amount of study done and also have a break because you will NOT stop until you walk out of that final exam.
I have a busy holidays. 3 assignments and study for my own exams 4 weeks after these holidays.