Intermittent Fasting Planner

Enter when your last meal was and this planner computes your whole fast: when the eating window opens and closes, and when each metabolic phase transition happens — the post-absorptive state, glycogen draw, the ~12h metabolic switch into gluconeogenesis and early ketones, fat-burning mode with early autophagy (16–24h), the ketosis shift (24–48h), and the peak autophagy zone (48–72h). The result is a printable, color-coded timeline (one row per day), a milestone table with real clock times you can set reminders for, and a copyable plain-text schedule. Six presets cover 12:12, 14:10, 16:8, 18:6, 20:4 and OMAD; the custom option supports any window from 2 hours up to a 72-hour extended fast. Phase onsets follow the widely-published fasting-stage model and are approximate — informational only, not medical advice.