Sleep Timing Regularity Analyzer
Analyse a multi-day sleep-timing diary with circular mean bed/wake times, midnight-aware deviations and paired time-in-bed windows.
Sleep diary timing workspace
Clock diary analysis; not the validated SRI
Your sleep timing pattern
23.86 minutes · bedtime timing RMS
Circular mean bedtime 23:36 · wake time 07:30
Full result table
| Day | Bedtime | Wake time | Time in bed min | Bed deviation min | Wake deviation min |
|---|---|---|---|---|---|
| 1 | 23:00 | 07:00 | 480 | -36.422931 | -29.972345 |
| 2 | 23:30 | 07:15 | 465 | -6.422931 | -14.972345 |
| 3 | 00:00 | 08:00 | 480 | 23.577069 | 30.027655 |
| 4 | 23:15 | 07:00 | 465 | -21.422931 | -29.972345 |
| 5 | 23:45 | 07:30 | 465 | 8.577069 | 0.027655 |
| 6 | 00:15 | 08:15 | 480 | 38.577069 | 45.027655 |
| 7 | 23:30 | 07:30 | 480 | -6.422931 | 0.027655 |
A descriptive clock-timing worksheet, not the validated Sleep Regularity Index and not a sleep-quality diagnosis. Window duration is time in bed, not measured sleep. Daylight-saving changes and dates are not modelled. Broadly ambiguous circular means are rejected.
Let’s work it out.
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How to use Sleep Timing Regularity Analyzer
- Enter bedtime and wake time for each day in the same order.
- A normal arithmetic average can place 23:30 and 00:30 near noon.
- A consistent schedule does not prove adequate or restorative sleep.
Worked example
Bedtimes 23:30 and 00:30 are centred around midnight rather than noon. A 23:00 bedtime and 07:00 wake pair gives an eight-hour window.
Formula, accuracy & limitations
Convert clock times to angles 2π × minutes/1440. Circular mean = atan2(mean sine, mean cosine). Deviations are wrapped to [−720,720) minutes. Timing RMS = sqrt(mean(wrapped deviation²)). Time-in-bed window = (wake − bed +1440) mod1440.
A descriptive clock-timing worksheet, not the validated Sleep Regularity Index and not a sleep-quality diagnosis. Window duration is time in bed, not measured sleep. Daylight-saving changes and dates are not modelled. Broadly ambiguous circular means are rejected.
These outputs use the stated model and your supplied inputs. A mathematically consistent model can still differ from personal measurements. Scenario curves and formula comparisons are not statistical confidence intervals.
Record several paired diary entries
Enter bedtime and wake time for each day in the same order. Use 24-hour HH:MM, including a leading zero where needed. Each wake is treated as the next clock occurrence within 24 hours; dates and daylight-saving transitions are outside this timing-only diary.
Use a midnight-aware centre
A normal arithmetic average can place 23:30 and 00:30 near noon. Circular averaging treats the clock as a circle and keeps that centre around midnight. The deviation plot then shows how many minutes each entry falls before or after its circular mean.
Separate regular timing from sleep quality
A consistent schedule does not prove adequate or restorative sleep. The paired window is only time in bed and does not deduct latency or awakenings. This page reports timing variability and clearly avoids calling the output a validated Sleep Regularity Index or diagnosing a sleep disorder.
Check a midnight example before averaging a diary
Bedtimes 23:30, 00:00 and 00:30 have a circular centre at midnight. With matching wake times 07:30, 08:00 and 08:30, each paired time-in-bed window is eight hours despite the changing clock times. The deviation chart describes timing around the circular centre, not whether the person slept for the whole window. A regular but short window and an irregular but long window describe different patterns; neither can be reduced to a diagnosis from these diary fields alone.
Frequently asked questions
Is this the Sleep Regularity Index?
No. The validated SRI uses sleep/wake state agreement across days. This tool summarises diary clock times and uses a different calculation.
Why are mean times circular?
Clock times wrap at midnight. Circular arithmetic prevents a pair near midnight from being averaged to a misleading midday value.
Does time in bed equal sleep duration?
The window includes time awake. Sleep latency and night awakenings are not entered, so the tool does not claim measured sleep duration.
Why reject widely scattered clock times?
When times are spread broadly around the clock, a circular centre can become ambiguous. Returning a precise-looking mean would conceal that ambiguity.
