Biorhythms 2026 v1.1.12 - Privacy

Privacy Policy

Last updated: 2026-06-12

This policy describes what the Biorhythms 2026 app does — and does not — do with your information. We use the words "app" to mean the Biorhythms 2026 mobile app and the web version hosted at cyclical.info, and "you" to mean the person using it.

Summary

The app is designed to work without an account, without ads, and without collecting personal data on a server. The values you enter are stored on your device. The only outbound network calls fetch moon-phase data so the chart can show the moon for the right date and hemisphere.

Data stored on your device

The following are stored in your device's local browser storage (or the equivalent WebView storage on Android). They never leave the device unless you choose to share a screenshot or export.

  • Birth date — entered by you. Used to compute your biorhythm cycles. Stored in localStorage under the key chartState.
  • Chart date — the date you are viewing on the chart. Defaults to today; you can change it. Stored in sessionStorage and cleared when the app session ends.
  • Display preferences — color mode (dark/light) and which rhythms are shown. Stored in localStorage.
  • Cached moon-phase data — a small cache of moon-phase results so the same date isn't fetched twice. Stored in localStorage under moonPhaseCache. Contains only date → phase mappings, nothing about you.

Uninstalling the app, or clearing site data in the browser, removes all of the above. There is no server-side copy to delete.

Device information used (not collected)

The app reads your device's IANA time zone (for example Europe/London) using the standard Intl.DateTimeFormat browser API. This is used only on the device to decide whether to render moon phases for the Northern or Southern Hemisphere. The time-zone string is not sent to any server.

Network calls the app makes

  • App download — the first time you open the web version, your browser downloads the app code from cyclical.info, hosted on Amazon CloudFront. CloudFront sees standard HTTP request data (your IP address, your browser's User-Agent, the URL you requested) like any website. The Android app bundles its code locally so it does not redownload on each launch.
  • Moon-phase data — when the chart shows moon-phase columns, the app calls a moon-phase service we operate (currently at an Amazon CloudFront URL). The request contains: the date or dates you are viewing, and an API key that is the same for everyone (used only to deter casual scraping, not to identify you). The service sees your IP address and User-Agent as part of any HTTP request. No birth date, name, or other personal data is sent.

Server access logs

Amazon CloudFront writes standard HTTP access logs for every request to cyclical.info and to the moon-phase service. These logs record the request date and time, the requested URL, the response status and size, the client IP address, and the User-Agent string. They do not contain your birth date, chart selections, or anything you typed into the app.

Purpose. We use the access logs only for operational diagnostics — checking that the service is up, finding bugs after a deploy, and looking at request volume and error rates. We do not use them for behavioural tracking, profiling, advertising, or per-user analytics. We do not link them to any user identity (the app has none).

Where the logs live. Logs are written to an Amazon S3 bucket by CloudFront, and we periodically download copies to the operator's own infrastructure so they can be searched and inspected. Those copies are then included in our regular backups (currently a daily backup to a private network-attached storage device under the operator's control).

Recipients. Access to these logs and their backup copies is limited to the operator of the service. We do not share them with any third party.

Retention. Logs are retained for as long as is needed for operational analysis and remain present in backup copies for as long as those backups are kept. There is no automatic deletion policy in place today. We are working towards an explicit lifecycle rule that deletes older logs from both the S3 bucket and the backups.

What we do not do

  • We do not show ads.
  • We do not use third-party analytics or tracking SDKs.
  • We do not collect crash reports in this release. (Future releases may introduce optional crash reporting; if that happens this policy will be updated and the change called out.)
  • We do not require an account, sign-in, or email address to use the app.
  • We do not sell, rent, or share data with third parties for advertising or any other purpose.

Children

The app is intended for a general audience. It does not knowingly collect personal information from children. Because birth date is the only input and it is stored only on the device, it is never transmitted to us or to a third party.

Third parties

The app's hosting and the moon-phase service both run on Amazon Web Services (CloudFront). AWS acts as our hosting provider. The access logs CloudFront writes for us are covered in the Server access logs section above. AWS's own privacy practices are described at aws.amazon.com/privacy.

Security

All network requests use HTTPS (TLS). Data stored on your device is protected by the device's own sandbox and operating-system protections. We have not commissioned an independent third-party security review of this app.

Changes to this policy

If we change how the app handles information — for example, by enabling crash reporting — we will update this page and change the "Last updated" date at the top. Material changes will be announced in the app's release notes.

Contact

For questions or requests about this policy, use the Support form.