Open data: the bedtime and caffeine tables

Table 1: bedtime for every wake-up time

96 wake-up times in 15-minute steps, each with the bedtime for 6, 5, 4, 3 sleep cycles: 384 bedtimes. Each is the wake-up time minus the cycles at 90 minutes and minus 15 minutes to fall asleep. Of the four options per row, the two for six and five cycles (192 of the 384 cells) give between seven and nine hours of sleep, the adult range; four cycles is six hours and three is four and a half.

Download bedtimes-by-wake-time.csv

Cycle length 90 min (range 70–120) from NINDS and AASM; 15 min sleep onset is our planning allowance.

Table 2: caffeine left, hour by hour

12 drinks at their typical serving, with the milligrams still circulating every two hours up to 14 hours, using a 5-hour half-life. Six hours after drinking, 5 of the 12 are already under 25 mg; the largest serving here, energy shot at 200 mg, still has 87 mg left at six hours and 38 mg at twelve.

Download caffeine-remaining-by-hour.csv

Doses: FDA, USDA FoodData Central, Mayo Clinic. Half-life 5 h is the healthy-adult average (range 1.5–9.5 h), Institute of Medicine 2001.

How to cite

Both files are released under Creative Commons Attribution 4.0: copy, adapt and republish them, including commercially, as long as you credit the source. A line like this is enough:

DozeClock (2026). Bedtime and caffeine tables. https://dozeclock.pages.dev/data/ (CC BY 4.0)

The underlying constants belong to the publications listed below, not to us; what is ours is the computed grid. The first line of each CSV carries the citation and the second the formula, both prefixed with # so spreadsheet tools can skip them.

What these tables are not

They are arithmetic on population averages. A real sleep cycle runs anywhere from 70 to 120 minutes and caffeine half-life varies about sixfold between people, so a row is a starting point for planning, not a prediction for one person. Found a wrong cell? Here is how to report it.