How many hours a day are actually yours
Every clock app can tell you how many hours are left today. That number is close to useless, because a large part of it is already committed to being asleep. Here is the subtraction that makes it usable, and what changes once you start reading the corrected figure instead.
It is nine in the evening. Your phone can tell you there are three hours left in the day. That is true and it is nearly worthless, because if you go to bed at eleven then two of those three hours are already spoken for and you have one.
The gap between those two numbers is the subject of this page. It is a small piece of arithmetic, it is not clever, and it changes what the number is for.
The subtraction
The raw figure is straightforward: hours left today is the time between now and midnight. Nothing about midnight is meaningful to you personally — it is a convention about when the date changes, and you are usually asleep for it.
The corrected figure needs one thing from you: when you sleep. Given a bedtime and a wake-up time, you can work out how much of the remaining day falls inside your sleep window, and subtract it.
- Hours left today = the time from now until midnight.
- Sleep still ahead = however much of that stretch falls inside your sleep window.
- Hours that are yours = the first minus the second, floored at zero.
That is exactly the calculation Life Progress performs, and the figure it shows on the main screen is the third one, labelled "Free today", with the sleep it removed noted underneath. The raw "hours until midnight" number is not shown at all, because once you have the corrected one there is no reason to look at the other.
Why it lands differently at different times of day
In the morning the two figures are close, because most of your sleep window is behind you. Through the afternoon they stay close. Then in the evening they split hard, and the split is the useful part.
Work an example with a bedtime of eleven and a wake-up at seven.
- At 14:00 the raw figure says ten hours and the corrected one says nine. Barely different; ignore it.
- At 21:00 the raw figure says three hours and the corrected one says two. A third of it evaporated.
- At 23:30 the raw figure says half an hour and the corrected one says zero. You are past your own bedtime, and the honest answer to "how much is left" is none.
The last case is the one worth having. A clock that says "thirty minutes left today" at half past eleven is technically correct and quietly encourages you to spend them. A number that says zero is saying something truer: whatever you do now is being taken out of tomorrow.
Why the sleep window has to be two times, not a duration
You could ask someone how many hours they sleep and subtract that. It would be wrong most of the time, because the question is not how much sleep you get but when it happens relative to now. Eight hours of sleep starting at eleven and eight hours starting at two in the morning produce completely different answers at nine in the evening.
So the input is two clock times, and the duration falls out of them. In Life Progress the bedtime and wake-up live on the time budget screen, the sleep total is derived from them rather than typed, and the arithmetic handles the wrap past midnight without you thinking about it. Change your bedtime and every figure on the main screen moves.
What this number is good for
Three things, in rough order of usefulness.
- Deciding whether something fits. "Two hours" and "one hour" are different answers to "can I start this tonight". The corrected number is the one that matches what is actually available.
- Noticing the evening earlier. The moment the free figure drops below an hour is a real boundary, and it arrives well before you feel it. People generally overestimate their remaining evening by about the length of their wind-down.
- Making the cost of a late night visible. When the free number hits zero and you are still up, you are borrowing. Seeing it stated is a mild, ignorable nudge rather than an alarm, which is the right strength for this.
What it is not good for
It is not a productivity measure and it does not know your commitments. Two free hours with a sick child in the house is not two free hours. The number subtracts sleep and nothing else, because sleep is the only commitment the app can know about without asking you to maintain a calendar — and an app that needs maintaining is one you stop using.
It is also not a sleep recommendation. It takes your bedtime as a fact, not as a target. If you tell it you go to bed at two, it believes you and does the arithmetic from there. It will not tell you that is too late, because that is not its business.
Seeing where the hours went, as well as how many are left
The remaining-hours figure answers a question about the next few hours. The more uncomfortable question is about all the other ones, and that needs a different view: how your twenty-four hours are divided in general, not today.
Life Progress handles that separately, in a time budget. You set the sleep window, then move the rest of your hours between work, commuting, meals, phone and self-care, adding your own categories for whatever is specific to you. If the pieces add up to more than a day it says so. And each category is then priced over your whole remaining life, which is a much sharper number than the daily one — that argument gets its own page on this site.
Doing it without an app
The arithmetic is small enough to do in your head, and it is worth doing once even if you install nothing.
- Write down the time you actually go to bed, not the time you intend to.
- Subtract that from now. That is your real remaining day.
- Do it again at nine in the evening, which is when the figure starts to be surprising.
- If the answer is regularly smaller than the thing you keep planning to do in the evenings, the problem is not discipline. It is that you were planning against the wrong number.
Frequently asked questions
How do I calculate how many free hours I have left today?
Take the time between now and your bedtime rather than between now and midnight. If your bedtime is after midnight, count through to it. That is the whole calculation — the only input that matters is the time you actually go to bed, not the time you plan to.
Why not just use "hours until midnight"?
Because midnight is a convention about the date changing and has nothing to do with you. In the evening, a large fraction of the time until midnight is sleep you have already committed to. The uncorrected number is systematically optimistic exactly when you are most likely to be looking at it.
Does Life Progress show the raw hours-left figure too?
No. It shows the corrected one, labelled "Free today", with the amount of sleep it subtracted noted underneath so you can see the working. The uncorrected number is not displayed anywhere, because there is no decision it helps you make.
Where do I set my bedtime?
On the time budget screen, as two clock times — when you go to sleep and when you get up. The sleep total is worked out from those rather than typed in, so it stays consistent, and it handles a bedtime after midnight correctly.
Does it account for work or other commitments?
Not in the daily figure. Only sleep is subtracted there, because sleep is the one commitment that can be known from a single setting rather than a maintained calendar. Work, commuting and the rest are handled in the time budget, which is a general picture of your day rather than a countdown for today.
See where you are, and leave a mark on the way through
Life Progress shows you where you stand in today, this week, this year and your life — hours left that are actually yours, days and weekends left this year, one cell per year for a whole life. Mark a moment in one tap and those marks colour the grid. Free, with no account, no server, no notifications and no permission prompts at all.