🟢 One session — A few hours, sittable in one gonext.js
'When do I actually need to leave?' math you do wrong under pressure
“I have a 9:00 flight / 7:30 reservation and I always misjudge the backwards math — travel time, buffer, getting ready — and end up rushing or late.”— r/getdisciplined ↗
The gap
Calendars store the event time, not the 'leave by' time. A reverse planner that chains prep + travel + buffer back from a fixed arrival — useful for ADHD/time-blindness — is a tiny tool with outsized daily value.
For
Chronically-rushed and time-blind people
Paste-ready build prompt
Build a 'leave by' reverse planner in Next.js. User enters the must-arrive time and a few backward steps (get ready 25m, travel 40m, buffer 15m); the app computes and prominently shows the 'leave by' and 'start getting ready' times, with a live countdown. First 3 steps: (1) arrival time + editable step list, (2) backward time computation, (3) a big, calm countdown view. Optional travel-time lookup later; keep manual entry first.