I surprised myself with high grades of 9's, and 7's. Never been academical, never been the smart kid of the class or anything like that. I started of doing bits of revision here and there before Christmas especially in my weaker subjects. As it got closer I did more, a bit here and there but still not tonnes. A week before I got completely serious and did hours 3/4 but made sure to take breaks. To be honest don't tire yourself out make sure to take breaks and do things you enjoy in between. On days before exams I only did a couple of hours and doing fun things in-between really did help. I'd say 5 hours on the weekend is excessive and you'll just bore yourself out. instead just spend 2 hours and enjoy the free time you have you still have plenty of time to take it at your own pace after all it's only February. When it comes to revising it's better to do less and spread it out than do loads in a chunk.