Because revising covered material and learning uncovered material are different jobs. If half the syllabus is still unseen, the plan needs time for genuine learning — slower, with different tactics — not just revision. Adjusting the estimate for coverage keeps the plan honest.

Start from your experience: count the topics, estimate the hours each needs to reach exam confidence, and total them. Most students under-estimate by a third, so add a buffer — the planner's start date absorbs the difference if you begin when it says.

The planner says so plainly and gives the recovery move: protect every remaining free hour, cut the lowest-value work, and tell your tutor and employer the exam dates so the week can bend around them. Being told the truth early is the whole value of the tool.