Privacy Policy

Effective September 3, 2026

Chronos is a calendar application for iPhone and Mac, built and operated by Glenn Joseph ("we", "us"). Chronos is designed so that your data stays with you: the app has no backend servers of its own, no user accounts of its own, no advertising, and no analytics about how you use it. The one thing we hold about you is the record of an optional Chronos Pro subscription, described below.

What Chronos accesses

Calendar data. With your permission, Chronos connects directly from your device to the calendar services you choose — Google Calendar, iCloud (CalDAV), and Microsoft 365 (Microsoft Graph) — to read and write your calendars and events, and to send responses to invitations you act on. This data flows directly between your device and the provider.
Contacts. With your permission, Chronos reads your device's contacts locally to suggest attendees while you type. Contact data never leaves your device except as attendee email addresses you explicitly add to an event, which are sent to your calendar provider to deliver invitations.
Location. With your permission, Chronos uses your approximate location to show local weather. Coordinates are sent only to the weather services below and are not stored by us.

Chronos Pro subscriptions

Chronos Pro is an optional subscription sold through Apple's App Store. Apple processes the payment; we never see your payment details. To unlock Pro features, restore your purchase on your other devices, and keep subscription records straight, Chronos uses RevenueCat, a subscription-management service. RevenueCat receives:

An anonymous customer ID. A random identifier created the first time Chronos runs and kept in the device Keychain. It is not derived from your name, Apple ID, or email address.
Your purchase history. The App Store record for Chronos Pro: which plan you chose, when it started, when it renews or expires, and whether a free trial is active. It contains no payment details.
Your email address. When you connect a calendar account, Chronos attaches that account's email address to your subscription record so that, if you contact us for help, we can find your subscription. Only the first account you connected is used, and the address is removed from the record when you remove your last calendar account from Chronos.
Basic device details. The app version, device model and operating system version, and the country the request comes from.

We use these records to unlock what you paid for and to see aggregate subscription figures, such as how many free trials convert. They are never used for advertising and never shared with anyone else. RevenueCat processes them on our behalf under its own privacy policy.

Where your data lives

Sign-in credentials (OAuth tokens, app-specific passwords) are stored in the device Keychain, on your device only.
Calendar and event data is cached on your device so the app opens instantly. Removing an account, or deleting the app, removes this data.
We operate no servers. We cannot see your calendars, events, contacts, credentials, or location — architecturally, they never reach us.
The only data about you held outside your device and your calendar providers is the Chronos Pro subscription record at RevenueCat described above.

Google user data

Chronos's use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements. Specifically: Google Calendar data is used only to display and manage your calendar inside the app at your direction; it is not transferred to anyone other than Google, not used for advertising, and not read by humans.

How we protect your data

Chronos protects sensitive data — including Google user data — with the following mechanisms:

Encryption in transit. All communication with Google, Apple, and Microsoft calendar services, and with RevenueCat, uses TLS (HTTPS) encryption. Chronos never transmits calendar data over unencrypted connections.
Encryption at rest. OAuth tokens and app-specific passwords are stored exclusively in the Apple Keychain, which encrypts them at rest using hardware-backed keys on your device. Cached calendar data is stored inside the app's sandboxed container, protected by Apple's built-in Data Protection (file-level encryption tied to your device passcode).
OS sandboxing. Chronos runs in Apple's app sandbox, so other apps cannot read its data.
Least-privilege access. Chronos requests only the OAuth scopes it needs to display and manage your calendars, and you can revoke that access at any time (see below).
No server-side copies. We operate no backend servers, so no copy of your calendar data exists outside your device and your calendar provider — there is no server of ours for anyone to breach. The subscription record at RevenueCat contains no calendar data.

Data retention and deletion

Because Chronos stores your calendar data only on your own device, retention and deletion are in your control:

Retention. Google user data (your calendar and event data) is cached on your device only for as long as the associated Google account remains connected in Chronos. We retain no copies of Google user data on any server, and we retain nothing after you disconnect an account.
Deletion. To delete Google user data from Chronos, remove the account in Chronos → Settings, which immediately deletes its cached calendar data and stored credentials from your device — or simply delete the app, which removes all data it stored. You can additionally revoke Chronos's access at myaccount.google.com/permissions, after which Chronos can no longer access your Google data.
Provider copies. Deleting data from Chronos does not affect the data held by your calendar provider (e.g., events in Google Calendar itself), which remains governed by that provider's own policies and controls.
Subscription records. RevenueCat keeps your Chronos Pro record for as long as it is needed to honor your purchase, including restoring it on a new device. Removing your last calendar account removes your email address from it. To have the whole record deleted, email us at chronosappsupport@gmail.com. Deleting it does not cancel a subscription — you manage that in your Apple ID settings — and Apple keeps its own purchase records under your Apple ID.

Third-party services

Your calendar providers (Google, Apple, Microsoft) receive the calendar operations you perform and are governed by their own privacy policies.
Apple Weather (WeatherKit) and Open-Meteo receive approximate coordinates to return forecasts.
U.S. EPA AirNow receives approximate coordinates to return air-quality observations.
Apple Maps is used to display event locations and suggest addresses as you type.
Apple's App Store processes Chronos Pro payments and holds the purchase records under your Apple ID.
RevenueCat stores the subscription records described above.

What we don't do

No advertising, ad tracking, or cross-app tracking of any kind.
No analytics or telemetry about how you use the app. The only usage figures we see are aggregate subscription numbers from RevenueCat.
No selling, sharing, or transferring of your data.
No collection of your calendar, contact, credential, or location data — none of it ever reaches us, so there is nothing of that kind for us to retain or delete.

Revoking access

You can disconnect an account in Chronos's Settings at any time, which deletes its credentials and cached data from your device. You can also revoke Chronos's access from your provider: Google, Apple ID (app-specific passwords), or Microsoft.

Children

Chronos is not directed at children under 13 and does not knowingly collect personal information from them.

Changes

If this policy changes, the updated version will be posted at this address with a new effective date.

September 3, 2026. Added the Chronos Pro subscription section: what RevenueCat receives, including the email address of your first connected calendar account, and how to have that record deleted.
July 30, 2026. First published.

Contact

Questions? Email chronosappsupport@gmail.com.