The University Library is open 24/7 except during the summer vacation and over Christmas. We open 24/7 because our previous students asked us to. This does not mean that you should study at all hours! We do not believe that studying into the small hours is a healthy option for most people, and you will still have to turn up to morning lectures and practicals. No-one wants you to work yourself into a stupor and then miss a vital exam because you have been studying and revising for so long! And yes, sadly that has happened before. Life likes to remind those who struggle, however slightly, that it is generally very unfair.
However you choose to study, please make sure you get enough, regular sleep and that you stay well and rested. University is supposed to be an enjoyable, three-year experience. It is a long-distance event, not a sprint. Start studying now and pace yourself to survive and thrive!