Deadline Backwards Planner
Given a deadline and the total hours a project will take, figure out what date you should start and how many calendar days you'll need.
Limitations: Treats every non-day-off day as available; does not honor specific calendar holidays. Does not spread effort unevenly (e.g., heavier weeks before the deadline).
What to do next: Pick a realistic "hours per day" — 2–3 hours of focused work is what most people sustain over weeks. Add a buffer of at least 1–2 days before the real deadline for review and polish.