Why an even split fails
The usual timetable gives six subjects an hour each. That feels fair, and it is the reason people fail one paper while over-preparing for another. An hour spent on the subject you already understand buys you almost nothing; the same hour on the one you are behind in is the difference between 38 and 55.
Fairness across subjects is also the wrong axis, because exams do not arrive together. Three weeks out, a chemistry paper and a statistics paper sitting nine days apart deserve very different shares of Tuesday. This planner scores each subject on difficulty and on how close its exam is, then divides the day in that proportion.
The scores are recomputed for every day in the plan rather than once at the start. So a subject that looks minor in week one steadily takes over the fortnight before its paper, and a subject whose exam has already passed drops out entirely instead of quietly holding on to an hour a day.