Backcast

Inspiration

Students plan forward: start whenever, work until done, and hope the deadline is still far away. That is how hackathon entries, assignments and applications get missed. We wanted a tool that answers one question first: when is the latest moment I can start and still finish?

What it does

Backcast plans backward from a deadline.

• You enter the deadline, a safety buffer (20% by default) and your steps in order, with minutes for each. Steps can be marked optional (polish, extras).
• It computes the latest start and end time for every step, counted back from the deadline, and the single "Start by" time.
• A badge shows On track, Start now (less than 30 min of slack) or You are already late.
• If you are late, it tells you what to cut: it drops the longest optional steps first until the required work fits, and if even that is not enough it says honestly how many minutes you are still short.

Who it is for

Students juggling assignment, exam, application and hackathon deadlines, especially the ones who start "later" and run out of time.

How we built it

• One pure function, backcast(deadline, steps, now, bufferPct), with no dependency on the page (backcast.js), plus a small vanilla HTML/CSS/JS interface. Everything runs in the browser; nothing is uploaded.
• Tests: node test.js covers on-track, start-now, late-with-cuts, still-short-after-cuts and buffer cases (4 scenarios, all passing).
• Deployed on GitHub Pages. Demo video narrated with a neural text-to-speech voice (edge-tts) over real screenshots of the app.
• AI-assisted development (Claude) was used for coding and the video pipeline, as allowed by rule 5.

What we built during LovHack Season 3

Everything. The repository was created during the build period (Oct 4, 2026 EDT); no code, design or template existed before the event. Open-source tools only (Playwright for screenshots, ffmpeg, edge-tts).

Challenges

Making "late" honest: our first version suggested cuts even when cutting optional steps could not close the gap. We added the remaining-shortfall check and a test for it.

What's next

Calendar export (.ics) for each step, and a shared link so a team can see the same backward plan.

Try it

• Live demo: https://ryugi62.github.io/backcast/
• Code: https://github.com/Ryugi62/backcast

Built With

• claude
• css3
• edge-tts
• github
• html5
• javascript
• playwright