How many hours holds your day?
Fourteen questions about your rhythm — sleep, light, caffeine, the evening. At the end: your day type, a score out of 14 hours and a map of where those hours go.
The mechanism of circadian clocks won the 2017 Nobel Prize in Medicine. Every question has a “why it matters” button — if you want to go deeper.
Answers never leave your browser — everything is computed on your device
Where the hours go
Hours don’t vanish without a trace — every lost one has a source in your answers. Remove the source — the hour comes back.
Where the 14 comes from
In an adult, about fourteen hours pass from morning light to the opening of the “melatonin window” — that’s how long the stable part of the day holds. The mechanism of the internal clock is described at the gene level — the 2017 Nobel Prize in Medicine. The test assesses how much your lifestyle helps that window stay open: —
What your answers show
Where to start
A day, built by the hours.
Three formulas of fermented plants — A.M., NOON and P.M. — into three parts of the day. Twenty-four plants, six drops per serving, EU warehouse.
Want to measure more precisely?
This test is self-report: a few minutes about your typical day. The next step — Circadian App from Fourteen Hours: it reads your tracker data (sleep, heart rate, heart-rate variability), builds a forecast for the coming hours and runs an AI coach that suggests one small habit a week.
The app is included in the Fourteen Hours subscription at no extra cost and is still in development — the page shows what’s being built. Trackers don’t measure circadian rhythms directly: the app works with what the sensors record, which is more precise than any questionnaire — but it’s still not a lab.
Circadian App — what’s inside →Circadian Check is a project by circarythm.com.