Measure Time in Bed Across Midnight Without Losing Minutes — Free
Bed at 23:30 and up at 07:15 is 465 minutes in bed — if you count across midnight correctly. Log each night as minutes before and after midnight and see the shortest night, not just the average.
The proof surface
Hypnogram readers chart journal entries visually. This does the crossing-midnight arithmetic: bedtime minutes before midnight plus wake minutes after it, against a target you set.
Why the flat version breaks
Subtracting clock times naively
23:30 to 07:15 is not 7.15 minus 23.30 hours.
Judging sleep by time in bed
Minutes awake inside the window are invisible here.
Aiming at a number you will resent
The target is yours; the tool only measures the gap.
How to work the night window strip
Bed 30 minutes before midnight is 23:30; wake 435 minutes after is 07:15. The window is their sum, 465 minutes — no clock arithmetic, no am/pm slips.
Enter the time in bed you actually aim for, in minutes. The sample aim is 480; both logged nights miss it, and Tuesday’s 405 is the floor the summary reports.
If you sleep 0 minutes before midnight and wake 420 minutes after, the window is 420 — the edge sample. Wake offsets must stay below 1440 minutes; use the night you went to bed as the row label.
The summary reports the shortest window because one bad night matters less than a floor you keep hitting. Time in bed is not sleep; if windows look right and you still struggle, that is a conversation for a clinician.
What the night window strip replaces
| Question | Before | Visible working |
|---|---|---|
| Subtracting clock times naively | 23:30 to 07:15 is not 7.15 minus 23.30 hours. | Keep the aim honest |
| Judging sleep by time in bed | Minutes awake inside the window are invisible here. | Nights inside one calendar day are fine |
| Aiming at a number you will resent | The target is yours; the tool only measures the gap. | Read the pattern, not one night |
A local arithmetic aid replaces hand calculation, not expert review. No paid AI service is needed.
Run it on the samples, right here
FIRST-LOAD
Input is processed locally and a draft is saved automatically in this browser profile when storage is available. Reset to sample clears that draft; Pro history has its own clear button. A state link encodes your inputs in its URL: share only non-sensitive rows. Browser history, clipboard and anyone receiving the link may retain it. Optional AI use below leaves this device; it is not required.
Arithmetic on times you enter. Time in bed is not sleep duration or quality, and this is not sleep medicine or a diagnosis; discuss persistent problems with a clinician.
Data note: Everything runs in this browser tab on the night window strip: your night | bedtime minutes before midnight | wake minutes after midnight stays on this device, nothing is uploaded, and the reading is rebuilt only when you press run.
Go deeper: the companion app files the same reading as a paper ticker strip
The article demo above runs without limits. The companion app keeps a local history, exports the rows as CSV, prints the night window strip reading, and holds your drafts on this device — one free run, then $ 4 one-time for the layer that keeps filing.
The night window strip reading is complete for free. The optional $4 layer adds print, row CSV and the last five local reading summaries; it does not add hidden answers. Checkout is not configured yet; the article demo remains unlimited.
Open the measure time in bed across midnight without losing minutes companionBoundary
Arithmetic on times you enter. Time in bed is not sleep duration or quality, and this is not sleep medicine or a diagnosis; discuss persistent problems with a clinician.
What this is built on
- Method: If you sleep 0 minutes before midnight and wake 420 minutes after, the window is 420 — the edge sample. Wake offsets must stay below 1440 minutes; use the night you went to bed as the row label.
- All sample records are invented examples. The app does not fetch measurements, policies, files or personal records.
- Google’s official pricing page, fetched 2026-09-28, lists free-tier access including AI Studio. Optional formatting only; limits and availability can change. Free-tier content may be used to improve products. Never paste private records there.
Before: 23:30 to 07:15 is not 7.15 minus 23.30 hours. After: the night window strip shows the working beside each named row so the reader can change the assumption and inspect the consequence.
Optional AI formatting, not calculation
For this night window strip, use the free AI Studio interface only if available to you, with no paid API key. Manual entry completes the same workflow for free. Supply only fictional or non-sensitive notes. Review its output against the source; never paste unresolved questions into the numeric rows.
Format my non-sensitive notes for a night window strip. Return plain rows only: night | bedtime minutes before midnight | wake minutes after midnight. Preserve supplied quantities exactly. Do not guess missing values; list questions separately. Do not calculate or add advice. I will check every row before pasting into the local tool.
Accepted schema: night | bedtime minutes before midnight | wake minutes after midnight. No AI response is executed as code.