Material learned on the last day rarely shows up in your answers. Material revised on the last day almost always does. Those two sentences decide most of what the final twenty-four hours should contain, and the list of things not to do is longer than the list of things to do.
Most students spend that day badly: they open a topic they never studied, panic, sit up late and walk into the exam tired. The last day is for consolidation, not acquisition.
Should you study something new?
No, with one exception. Opening an untouched topic the day before does two kinds of damage: it steals time from revision, and half-learned material tangles with what you already know. The biggest losses in exams come from topics that sit in the "just learned it, not quite" state.
The exception is a small, self-contained thing, a single formula, a definition, one exception to a rule, which can be closed in half an hour. Make that call honestly, though; a unit begun with "I will knock this out quickly" usually takes three hours.
How many hours on the last day?
Two or three, split into blocks. Eight hours is neither possible nor useful, and the tiredness takes more than the knowledge gives. Forty-minute blocks with real ten-minute breaks fit more revision into the same window.
The time of day matters too. For a morning exam, push the work into the afternoon rather than the evening, which protects your sleep. The last hour squeezed in after eight at night does damage in proportion to how much it delays going to bed.
What exactly should you revise?
Three things: your list of past mistakes, your formula and definition cards, and your own summaries. The order is not random; the easiest marks come from not repeating an error you have already made.
The mistake list pays most. If you noted where you went wrong during the week, reading those lines converts directly into marks. If you did not, a quick pass over the wrong answers in your practice does the same job more slowly.
The form of revision changes the result as well. Rereading notes produces a feeling of familiarity without exercising recall. Closing the book and explaining the topic out loud to yourself exposes far more gaps in the same time, and stopping to check wherever you stumble beats reading from start to finish. If the exam asks for written answers, add one step and write a few answers out in full sentences.
Do late nights work?
They are a bad trade even in the short run. Sleep's role in settling what you learned is well established, and two hours gained after midnight are paid for with the next day's attention. On exam day attention can matter more than knowledge: misreading a question costs more marks than a topic you never studied.
Lack of sleep hurts most in papers with long texts. A tired reader returns to the same line three times and runs out of time. Sleep and cognitive performance goes into the mechanism.
Trying to fix your sleep schedule the night before does not work either. Someone who normally sleeps at one will mostly lie awake if they try for ten. Shifting a schedule takes a few days; the one thing available on the final night is going to bed an hour earlier than usual.
What about the exam morning?
Light revision and breakfast, and no new questions. A question attempted and failed at eight in the morning keeps your confidence down until the exam starts. Formula cards and summary notes are enough.
On caffeine, the rule is not to exceed your usual amount. Two coffees on the morning of an exam, for someone who does not normally drink coffee, produces restlessness rather than focus; caffeine and focus covers the detail. Breakfast only needs to be light; there is no special menu.
Then the bag: pens, eraser, calculator if allowed, identification. Packing it the night before is the simplest way to keep the first half hour of the morning calm.
What if anxiety rises?
Take a short break rather than pushing through. Anxiety climbing on the last day is normal and it usually feeds on the thought that there is not enough time. What reduces that thought is not more work but a shorter list: cut what is left to three items and finish only those.
Physically, the simplest thing that helps is a walk. Twenty minutes outside beats twenty minutes at a desk learning nothing. For anxiety that runs higher than this, what actually helps with exam anxiety and focus and memory techniques for exam season give fuller methods.
What is the most common mistake in the last day?
Talking about the exam with classmates. The evening phone call about whether a topic will come up almost always raises anxiety, and it spreads guesses as if they were information. Knowing what someone else has finished does not change your score.
The second is sitting a full mock paper. A mock is a measuring tool, and its value lies in being able to act on the result. The day before, there is no time to act; a low score only damages morale. If you want a mock, sit it two or three days out and spend the final day on its mistakes instead.