Enter the time you start and we'll tell you exactly when your 17-hour fast ends — plus when key milestones land along the way.
Once your fast ends at 11:00 PM, break it gently — water first, then protein and fiber rather than sugar. The milestones above are typical estimates; your body's exact timing varies with your last meal, activity, and sleep.
Fast Goblin counts your fast live, alerts you at each milestone, and tells you the exact moment you hit your goal. No spreadsheet, no account, all on your iPhone.
This calculator-style page answers the timing question first, then shows how to track the same window in Fast Goblin.
| Calculation | Result |
|---|---|
| Start time | 6:00 AM |
| Fasting duration | 17 hours |
| End time | 11:00 PM |
| Day | same day |
6:00 AM + 17 hours = 11:00 PM (same day)
For a simple example, start your timer at 6:00 AM, keep the fast going through the full 17 hours, and break it at 11:00 PM. If that window feels awkward, move the start time instead of changing the whole plan.
Fast Goblin can save the calculation by letting you start the fast and see the end time automatically. No more checking the clock twice and still being unsure.
Fast Goblin can save the calculation by letting you start the fast and see the end time automatically. No more checking the clock twice and still being unsure.
It ends at 11:00 PM the same day.
For overnight or multi-day fasts, yes. The page shows whether the end time falls on the same day or a later day.
Yes. Use the calculator index or set a custom timer in Fast Goblin.
Free on the App Store, private by design. Android coming soon.