When can I eat next?
Every fasting schedule, no matter the ratio, comes down to the same single question at some point in the day. Here's why that question is harder to answer in your head than it looks, and how a timer settles it in one glance.
Why the question is trickier than it seems
On paper, working out when your window opens is simple addition: start time plus fasting hours. In practice, a few things make it easy to lose track. You might not remember your exact start time by hour six. Your schedule might not start at a clean hour. And if life shifts your start time by twenty minutes one day, that shift carries through the rest of the day too. None of this is complicated, it's just fiddly enough that doing it by memory gets old.
The same question, four schedules
Whatever schedule you're on, the underlying question and the underlying math are the same: window open time equals fast start time plus fasting hours. Only the numbers change.
| Schedule | Not eating | Eating window | Example window |
|---|---|---|---|
| 16:8 | 16 hours | 8 hours | 12:00 PM to 8:00 PM |
| 18:6 | 18 hours | 6 hours | 1:00 PM to 7:00 PM |
| 20:4 | 20 hours | 4 hours | 2:00 PM to 6:00 PM |
| OMAD | ~23 hours | ~1 hour | 6:00 PM to 7:00 PM |
| Custom | You choose | You choose | Whatever fits your day |
What a timer actually does
A fasting timer's whole job is to hold that one piece of arithmetic so you don't have to. WhenCanIEat starts counting the moment you begin a fast, shows a live countdown to your window opening, then switches to counting up once it's open, so you always know one of two things at a glance: how long until you can eat, or how long you've been able to. There's no separate step to check, no need to recall your start time, and no risk of the math drifting over the course of the day.
Streaks answer a related question
Alongside "when can I eat next," the other question people tend to want answered is "how am I doing on this routine." That's what the streak counter is for: each completed fast adds to your streak, and your full history is right there from day one, so the pattern of your own routine is visible without digging through anything.
One app, any schedule
Whether you're running 16:8, 18:6, 20:4, OMAD, or a custom window that doesn't match any of those ratios, the answer to "when can I eat next" works the same way in the App: open it, look at the countdown, done.
Stop doing the math yourself
Full app free for your first 2 fasts, including custom schedules. Then $0.99 a month or $9.99 a year to keep going.