Building Bed Debt

Sleep apps compare you to a number that was never about you. Building Bed Debt builds a personal range from the sleep YOU log, shows you that range on screen, and shows how it changes as it learns. It describes your recent ordinary nights; it is not a measurement of a biological need. WHY THE MOVING PART MATTERS Some sleep trackers adapt to your data, but the change can be hard to see. Building Bed Debt shows the estimate's movement over time. It does not claim to identify the particular night that moved each point. WHAT THE RESEARCH ACTUALLY SAYS, INCLUDING THE INCONVENIENT PART We went looking for a simple rule — something like the calorie world's "bodyweight times twenty-four" — that would predict your sleep need from things you already know. We found no evidence for one, and we're not going to pretend otherwise. We found no study showing that body weight predicts how much sleep a person needs. Studies have reported different results when comparing how long women and men sleep. Being a morning or an evening person is a good guide to WHEN you sleep; in the one study we read that tested it, it did not track how much sleep people needed. Age moves the typical range by roughly an hour to an hour and a half across the adult years, but within any age people differ by as much or more — useful for a band, not for a person. Researchers measure one person's sleep need in a lab: they allow extra time in bed for days and watch where the sleep settles. This app does not do that. In one small study of that kind, fifteen young men of nearly identical age settled anywhere from 7.3 to 9.3 hours, and their usual sleep predicted that only loosely. That is a wide spread among people who look the same on paper. It is also exactly why a single population number is the wrong tool. SO THE APP WATCHES INSTEAD OF ASSUMING Building Bed Debt learns from your recorded nights, which are ordinary nights and include ones cut short by an alarm or a busy week, so its range describes your recent sleep. It tells you how many of your last 90 nights the estimate is based on, and leaves it at that instead of presenting a guess as a fact. WHERE THE DATA COMES FROM Apple Health. If your watch or ring writes compatible sleep records to Apple Health, the app can read those records after you allow access. What arrives depends on that device or app and its Health sharing. You can also add nights manually. FOR THE WEEKS WHEN IT GOES WRONG Some weeks are bad and no app fixes that. A new baby, a deadline, illness, a stretch of nights that were never going to be good ones. Building Bed Debt has something to say in those weeks that isn't a red number and a guilt-trip. When it spots a run of short nights it asks you one question, and your answer decides what it does next — a week you can do something about and a week you simply have to get through are not treated the same. WHAT IT WILL NEVER DO It won't hand you a population target. The range on screen describes your recent recorded sleep, built from your own nights. It won't score your night out of a hundred. It won't tell you that you've ruined something. If you sleep badly, you already know — the app's job is to tell you what it means over weeks, not to grade last night. No streaks. No badges. No notification designed to make you feel behind.