About
A small site that does one sum and shows its working.
The idea
Many sleep calculators give you a confident time and say little about where it came from. The time is the product of two arbitrary numbers, and a ten-minute difference in one of them moves the answer by nearly an hour by the fifth cycle. Hiding that makes a subtraction look like a measurement.
DuskDial puts both numbers on the page, on sliders, and recalculates as you move them. You can reproduce every figure here on paper. That is the whole design.
What it will not do
- It will not tell you how much sleep you need. That varies by person and this site has no way of knowing yours.
- It will not claim that a bedtime makes anybody healthier, sharper or happier. Those are claims about a body, and a page of arithmetic cannot support one.
- It will not ask you to sign up. There is no account, no email capture and no newsletter.
- It will not send anything you type anywhere. Every calculation runs in your browser.
What is on it
A wake-time page for every quarter hour of the day, 96 in all, and a written account for 11 of the common alarms of what each asks of the evening and where it falls in daylight. A travel planner that knows 89 cities, with a written account for 10 routes of how the gap moves through the year. A shift rota planner with 6 named patterns to start from, and a page for each of 5 single shifts. Pages for 4 nap lengths, a week's tally, three tools, a clock-change planner, a notebook that fits a cycle length to your own mornings, and 7 reference pages on where the numbers come from. Every one of them works from the same two numbers, printed where they are used.
Using it offline
DuskDial can keep a copy of its main pages on this device, so they open with no connection. It does so only if you ask, here or on the offline page, which says what the copy holds, and the same switch removes it.
No copy of DuskDial is kept on this device.
Where the numbers come from
Two assumptions, printed on every page that uses them: a cycle of 90 minutes and 15 minutes to drop off. The reference pages name the published sources behind the first and say plainly that the second is a starting point, not a finding. Sunrise and sunset come from NOAA's solar equations, time-zone rules from the IANA time zone database, and the world map's coastlines from Natural Earth. The moon at the top of each page is drawn from the lunar colour map in the CGI Moon Kit by NASA's Scientific Visualization Studio, made from Lunar Reconnaissance Orbiter data; NASA material of this kind is generally not subject to copyright in the United States, and it is credited here as NASA asks. The sun is drawn by this site. The nap pages cite the break rules in the United Kingdom, South Africa and the United States, each linked to its government's own page.
How it is paid for
Advertising, once Google AdSense has approved the site; until then nothing is shown. When they run, adverts are placed by hand and kept below the answer rather than in front of it. Nobody pays to be mentioned here and there is nothing to buy. The privacy page says what the advertising means for you.
Corrections
A figure that looks wrong is the report we most want. Write to the address below with the page and the number, and it will be checked against the arithmetic and put right if it is wrong. Every change a visitor could see is dated on the What's new page.
Who runs it
Inyonitech Solutions (Pty) Ltd, a company registered in South Africa. Corrections and complaints go to hello@duskdial.com, which is read by a person.