Terms of Service

1. The service

alarm-clock.org provides an alarm clock, countdown timer, stopwatch, world clock, a library of curated event countdown pages, sunrise and sunset times, moon phases and moonrise, tide predictions, a set of astronomy simulators (the Sun, Earth and Moon simulator, the solar system simulator and its per-planet pages, and rocket launch windows), and a guide for classroom use — all free, with no account or sign-up required. The alarm clock, timer, stopwatch and every simulator run entirely in your browser, and the clock tools save their settings on your own device (see our Privacy Policy) — we do not maintain a permanent server-side database of your alarms, timers, or stopwatch sessions. Every astronomical figure on the site is calculated in your browser rather than fetched from a live service, except the tide predictions described below. We don't offer a custom, user-generated countdown feature — every countdown page on the site is one we've written and curated ourselves.

2. Acceptable use

We no longer accept custom, user-generated countdowns. If you submit a message through our report, wrong-date, suggestion or promotion forms, it may not:

• Promote, glorify, or reference hate groups or hateful ideologies.
• Threaten, promote, or plan violence, harm, or attacks against any person or group.
• Harass, bully, defame, or target an individual.
• Contain slurs, vulgar, sexual, or otherwise inappropriate content.
• Be unlawful or intended to deceive or defraud.

We may disregard or remove submissions that violate this policy. You can report abusive content you find elsewhere on the site on our report page.

3. Alarm clock, timer & stopwatch reliability

Alarm clock. The alarm clock runs entirely in your browser and only rings while the alarm page (or its full-screen or floating window) is open, active, and your device is on. It will not ring if the tab or browser is closed, the device is asleep, restarted, or out of battery, if the browser suspends a background tab, or if your device is muted or in a do-not-disturb mode. Do not rely on this alarm for time-critical purposes — waking for work, travel, flights, medication, exams, or any situation where a missed alarm would cause harm or loss. Use a dedicated hardware alarm clock or your phone's native alarm app as a backup for anything important.

Timer & stopwatch. The countdown timer and stopwatch also run entirely in your browser and only count down, count up, or sound an alert while their page is open. Closing the tab, letting the device sleep, losing power, or a browser throttling a background tab can pause or stop them silently. Don't rely on them for safety-critical timing (cooking, medical dosing intervals, exercise limits, exams) without an independent way to confirm elapsed time.

World clock & displayed times. Times, time zones and daylight-saving adjustments shown across the site are computed from your device's clock and publicly available time zone data, for general reference only. We don't guarantee they match an official or legal time source — for legal, travel, or contractual deadlines, confirm the time with an authoritative source.

Settings for these tools (alarms, timer presets, stopwatch state, display colors) are saved only in your own browser's local storage — we do not maintain a permanent server-side database of them — so they aren't backed up and disappear if you clear your browser's site data or switch devices. Standard security, request, analytics, and abuse-prevention logs may still temporarily process information as described in our Privacy Policy.

4. Event dates & accuracy

We work to keep the dates on our public event pages (holidays, birthdays, sports, sales and more) accurate, but dates can change and errors happen, sale windows shift, ceremonies are rescheduled, and some dates are estimates until officially announced. Event information is provided "as is" without any guarantee of accuracy. Always confirm important dates with the official source before making plans. Spotted a mistake? Tell us on the wrong date page and we'll fix it.

5. Tide data (beta)

The tide pages (/tides/) are a beta feature. They display tide predictions and station information from NOAA CO-OPS — a third-party source we don't control — and that data may be incomplete, delayed, estimated, wrong, or unavailable at any time. Tide predictions are astronomical only: actual water levels are routinely changed by wind, storm surge, river flow, and barometric pressure, none of which this site displays or estimates.

This information is not intended for — and must not be used for — navigation, boating, diving, swimming or surf decisions, evacuation or flood-response decisions, or any decision where an error could pose a risk to life, health, safety, property, or money. For any such decision, use official sources: NOAA charts and tables, the National Weather Service, the U.S. Coast Guard, and your local authorities. Every tide station page links directly to NOAA's own prediction page for that location.

All tide information on this site is provided "as is," for general informational purposes only, entirely at your own risk. To the fullest extent permitted by law, alarm-clock.org and its operators disclaim all liability for any loss, damage, injury, or death arising from use of or reliance on this information.

6. Astronomy pages, simulators & educational content

The sun, moon, solar system and rocket launch pages (/sun/, /moon/, /sun-moon-earth-movement-simulator/, /solar-system-simulator/ and /rocket-launches/) are educational illustrations. Everything on them is computed in your browser from published orbital elements and standard astronomical formulas — nothing is looked up from a live feed — and each page states where its own figures stop being reliable.

They are not an ephemeris and not a navigation aid. Planet positions come from approximate Keplerian elements with per-century rates, good to a few arcminutes over roughly 1800–2050 and extrapolated beyond it. Moon phases, rise and set times, sunrise and sunset are solved for a flat, unobstructed horizon and do not model terrain, elevation, buildings, or local atmospheric refraction on the day. Do not use anything on these pages for navigation, aviation, surveying, agriculture, religious observance timing, legal or contractual deadlines, or any other purpose where being wrong by minutes — or by a degree — would matter. Use an official source.

Pictures are not to scale, and say so. Several of these drawings deliberately depart from true scale so that they fit on a screen and remain legible: the Sun, Earth and Moon simulator draws the moon far too close to the Earth and the sun far too close and too small; the solar system simulator draws the orbits to scale within each view but the planets themselves far larger than scale; and each planet is drawn from published coordinates and feature sizes rather than traced from a photograph. Where we take a liberty of this kind, the page prints the factor by which it is wrong. Read those notes before teaching from a picture.

Launch windows and flight paths are reference calculations, not mission plans. The trajectories shown are minimum-energy (Hohmann) transfers solved from the same orbital model — the cheapest possible route and the benchmark real plans are measured against. They assume coplanar orbits, ignore gravity assists, and ignore every operational constraint a real launch has. Real missions do not fly them. Nothing on these pages is engineering guidance.

Never look directly at the sun, with or without a telescope, binoculars, camera, or any unfiltered optic, and never use anything on this site to decide that it is safe to. Our sun pages give times and directions only; they are not eclipse-viewing guidance and do not assess viewing safety. Permanent eye injury can occur without pain and without warning. Follow guidance from an appropriate authority and use certified equipment.

Historical facts, mission details, discovery credits and open scientific questions on these pages are summaries written for a general reader, may be simplified, and may go out of date as science moves on. They are provided "as is" for general interest and education.

7. Classroom use & class requests

Teachers, schools, libraries and other educators are welcome to use this site in lessons, on a projector, and in materials for their own students, at no cost and with no licence needed. You do not need our permission to use the tools in class or to link to any page. Projector mode and the classroom guide are provided for that purpose.

The class request form. On our classroom page you can ask us to build something. That form is for teachers and other adults to submit on behalf of a class — it is not intended for use by children, and it should not be completed by students directly. Do not send us the name of any student, or any other personal information about a child. We do not want it, we do not need it, and we will delete it if we receive it.

We ask for a teacher name, a grade or year group, a city and region, an optional school year, and an email address so we can reply. We use those details only to answer you and, if you have asked us to, to credit the class as described below. See our Privacy Policy for how submissions are handled.

Credit, if we build it. If we build something because your class asked for it, and you have left the credit box ticked, we may publish a line naming the teacher, the grade or year group, the town or city and region, and the school year on the resulting page — for example, "Ms Thomas’s 3rd grade class, 2026–2027 school year — Chico, CA". We will not publish student names, the school’s name, your email address, or anything else you send us. Untick the box and we will publish nothing. If you change your mind at any time, write to us through the report page and we will remove the credit.

No promise to build anything. We read every request and we will do our best to reply, but we cannot promise that any particular idea will be built, that it will be built within any period, or that it will work the way you pictured it. Requests that can be computed from real motions and measurements are the ones most likely to be built; nothing on this site should be planned around on the strength of a request.

Please make sure you are permitted to contact us in this way under your school or district’s policies before you send anything.

8. No warranty & limitation of liability

The service — including the alarm clock, timer, stopwatch, world clock, countdowns, tide information, the sun, moon, solar system and rocket launch pages, and every simulator and calculation on them — is provided "as is" and "as available," without warranties of any kind, express or implied. We don't guarantee the site will be uninterrupted or error-free, or that any alarm, timer, reminder, countdown or date will be accurate or will fire, sound, or display as expected. To the fullest extent permitted by law, alarm-clock.org and its operators are not liable for any indirect, incidental, special or consequential damages, including missed alarms, missed timers, missed events, missed sales, plans made in reliance on any tool on this site, or any decision or action taken in reliance on tide or marine information, on any astronomical time, position or prediction shown here, or on any simulation, launch window or educational statement on this site.

Full screen and bedside display modes are meant to be used with your device plugged in and left on for extended periods, including overnight. That use is at your own risk: to the fullest extent permitted by law, alarm-clock.org and its operators are not liable for device damage of any kind, including screen burn-in or image retention, overheating, or battery wear, arising from leaving a display on for extended periods. Follow your device manufacturer's guidance on safe charging, screen brightness and overnight use — see screen warnings.

9. Third-party links & affiliate disclosure

Event pages may link to official sites, retailers and other third-party resources for your convenience. We don't control those sites and aren't responsible for their content, availability or terms. A link is not an endorsement.

Some pages (like our timer's shopping suggestions) include Amazon affiliate links. As an Amazon Associate, alarm-clock.org earns from qualifying purchases at no extra cost to you — see our Affiliate Disclosure for details.

10. Changes to these terms

We may update these terms from time to time. The current version always lives at this address, and continued use of the site after a change means you accept the updated terms.

11. Your content & responsibility

You are solely responsible for the alarm and timer labels you create, and any message you submit through our report, wrong-date, suggestion or promotion forms. Don't include other people's private information, or names, logos, images or text you don't have permission to use. Alarm and timer labels are saved only in your own browser — we do not maintain a permanent server-side database of them. Standard security, request, analytics, and abuse-prevention logs may still temporarily process information as described in our Privacy Policy.

12. Copyright & DMCA notices

We respect intellectual property and expect users to do the same. The site's own design, code and original artwork are owned by alarm-clock.org. If you believe a page on this site infringes your copyright, send a notice through our report page including: (1) identification of the work, (2) the exact page URL, (3) your contact information, (4) a statement that you have a good-faith belief the use isn't authorized, (5) a statement, under penalty of perjury, that your notice is accurate and you're authorized to act for the rights holder, and (6) your physical or electronic signature. We remove or disable material in response to valid notices and may block repeat infringers.

13. Feedback & suggestions

If you send us an idea, suggestion or feature request (including through the "Share an idea" box on this site), you agree we can use it freely — to build, improve, or promote the site — without any obligation to compensate you, and, except as set out below, without any obligation to credit you. The one exception is a class request: where a class asks us for something through the classroom page and has left the credit box ticked, we intend to credit that class as described in Classroom use & class requests above. That is a commitment about crediting only; the licence in this section still applies, and it does not give anyone rights in what we build.

14. Privacy

How we handle data is covered in our Privacy Policy. The short version: no accounts, no stored events, alarms and timer settings stay on your own device, and any email address or class detail you send us is used to reply to you and — for a class request, if you asked for it — to print the credit described above.