What this version does
Effective November 11, 2026. This policy describes the Sleep Calculator website, including local calculations, browser settings and website analytics. For the iPhone app’s data practices, see the Sleep Planner Privacy Policy.
Local calculations
Your selected times, dates, time zone, latency, cycle length and age-range selection are used locally. They are not sent to a Sleep Calculator calculation API. Results are not automatically saved, emailed or placed into shareable URLs. Reloading the page resets the form.
The browser reads your device’s current time and configured time zone to provide local calculations. The site does not request precise location, microphone, camera, wearable data or health records.
Theme preference
The light/dark preference is stored locally in your browser. This is a display setting, not a health profile. You can clear it through your browser’s site-data controls. If local storage is unavailable, the calculator still works and the default night theme is used until changed during the visit.
Copying and sharing results
Copy result writes the displayed plan to your clipboard only when you choose that action. Share result uses your browser’s share interface if available; otherwise it offers a copy fallback. The shared text includes the times, dates, time zone, calculation assumptions, Sleep Calculator name and the current page’s clean URL.
If you share that text with another app or person, the destination’s privacy practices apply. The site does not add your sleep inputs to URL query parameters. Tracking parameters already present in a page URL are removed from the link used in the result text.
Hosting and ordinary requests
Opening the website sends ordinary requests for pages, fonts, scripts and images to its host. Fonts are served from the same site. Hosting infrastructure can process technical information such as IP address, request URL, browser headers and security logs to serve and protect the site.
Cloudflare processes requests for the hosted website under its own terms and privacy policy. This project does not define or promise a particular provider log-retention period.
Analytics and advertising
The published website uses PVUV.ai and Ahrefs Web Analytics to understand visits, traffic sources, page usage and performance. Their scripts can receive page URLs and query parameters, referring pages, browser and device information, and interaction events. Requests to these services also include technical information such as your IP address.
PVUV.ai uses first-party cookies and local storage to recognize visitors and sessions. It collects interaction and browser-environment signals to help distinguish people from automated traffic, along with usage and performance information. Click analytics can include button labels, including planning choices displayed by the calculator. You can remove its stored identifiers through your browser’s site-data controls. See PVUV.ai’s privacy information.
Ahrefs describes its analytics as cookie-free. It uses a daily pseudonymous identifier to count visitors and reports information such as pages viewed, referral sources, browser, device and approximate location. See Ahrefs’ data collection explanation.
Our calculator also emits local interaction events within the browser. These custom events are separate from the providers’ automatic tracking. The website does not currently forward them to either provider. The calculator uses your inputs locally for calculations, and the site does not place those inputs in page URLs.
Analytics may be limited by your browser’s privacy settings or content blockers. The calculator works when analytics requests are blocked. Reserved advertisement areas currently show no ads.
Contact and external links
The Contact page identifies the support-channel status. If email support is activated and you send a message, the mailbox provider and site operator will receive what you include. Avoid sending health records or sensitive personal details. There is no contact form uploading messages from this site.
Links to educational sources take you to external websites with their own policies. This site does not control their collection or content.