Delta Calendar Privacy Policy

Last updated: Sept 7, 2025

Welcome to Delta Calendar. Your privacy is a top priority for us. This policy explains what data we collect, why we need it, and how we handle it, ensuring you have full control over your information.

Data We Access and Use

Location Data

• What: If you grant permission, we access your device’s latitude and longitude. You can also manually enter a city name.
• Purpose: This data is used exclusively to fetch relevant weather information for your location using Apple's WeatherKit.
• How: Your coordinates or city name are sent to Apple's Core Location and WeatherKit services to retrieve weather data.
• Storage: We do not store a continuous history of your precise GPS location on our servers. The specific city names and their coordinates that you use to fetch weather are saved as part of your app data, both locally and, if you have an account, on our servers.
• Control: You can revoke location permissions in your device settings or use manual entry at any time.

Health Data (from HealthKit)

• What: If you grant permission, the app accesses specific data types from Apple’s HealthKit. This can include, but is not limited to: step count, heart rate, blood oxygen, respiratory rate, HRV SDNN, VO2 max, environmental audio exposure, exercise minutes, stand hours, time in daylight, sleeping wrist temperature, blood glucose, and sleep analysis data.
• Purpose: The primary purpose of accessing this data is to display it within the app, allowing you to track and visualize your health trends over time. It is not used for advertising or data mining.
• How: Data is fetched from HealthKit upon your request and displayed within the app's interface.
• Sharing: Your HealthKit data is never shared with third parties. If you create an account, your metrics are securely stored on our servers for backup and sync. If you explicitly consent to our AI improvement program (detailed below), a fully anonymized version of this data may be used solely for our internal analysis to improve health features.
• Control: You have granular control over which HealthKit data types the app can access. You can manage these permissions at any time in the Apple Health app.

Chess Username

• What: Your Chess.com username, if you choose to provide it.
• Purpose: To fetch and display your chess ELO rating as a trackable metric within the app.
• How: Your username is sent to the public Chess.com API to retrieve your rating.
• Sharing: The username is sent to Chess.com but is not otherwise shared or linked to your other personal data by us.
• Control: This feature is entirely optional and can be enabled or disabled in the app's settings.

Data Storage and Security

• What: If you create a Delta Calendar account, your events, metrics, routines, and journal entries are synchronized and stored on our servers, up to your account's storage limit.
• How: When you have an account, your data is encrypted in transit (using TLS) and at rest on our servers.
• Security: We take the security of your data seriously. Our servers and data handling practices are designed to meet the high standards of privacy and security required by laws such as Canada's Personal Health Information Protection Act (PHIPA). We are in the process of undergoing a third-party audit to formally certify our compliance.

Optional and Anonymous Data Sharing for AI Improvement

To advance health insights for everyone, we are developing AI models to identify patterns between lifestyle and health. You can voluntarily contribute to this effort.

• What: You can choose to anonymously share your health and weather metrics. This is an opt-in feature presented during sign-up.
• How it Works: If you consent, we collect the relevant data points. All personal identifiers (like your user ID) are removed to ensure the data is fully anonymous. This data is then aggregated with data from other consenting users.
• Purpose: This aggregated, anonymous data is used solely by the Delta Calendar team to train our AI models. The goal is to improve the app and its health insights for the entire Delta Calendar community.
• Sharing: This anonymized data is for internal use only. We will not sell or share it with any third parties.
• Control: Participation is completely voluntary. You can provide or withdraw your consent at any time in the app's settings. Your decision will not limit your access to any of the app's features.

Data Sharing for Research Studies

We may partner with academic institutions, healthcare organizations, or other research groups ("Researchers") to conduct studies aimed at advancing scientific understanding. You may be given the opportunity to voluntarily participate in these studies.

• What: If you choose to join a study, you will be asked to consent to share specific categories of your data, such as health metrics, journal entries, or event logs ("Research Data"), with the designated Researcher. The exact data shared will be clearly outlined in the consent form for each specific study.
• Purpose: The purpose is to contribute to scientific, wellness, or academic research.
• How it Works: Participation requires an explicit opt-in action from you, typically by joining a study within the app and agreeing to its specific consent terms. Once shared, your Research Data may be de-identified (linking you only to a unique participant ID) and aggregated with data from other participants.

Important: Withdrawing Consent and Your Data Rights

To maintain the integrity and validity of long-term scientific research, your participation comes with specific conditions regarding your data rights:

• Right to Withdraw from Future Sharing: You have the right to stop sharing new data with a research study at any time. You can do this by leaving the study through the app's settings. This action is effective immediately and will prevent any of your future data from being collected for that study.
• Retention of Previously Shared Data: While you can stop future data sharing, this action does not apply retroactively. To ensure research results are not corrupted, you acknowledge and agree that you will not be able to delete your Research Data that was already collected while you were an active participant.
• Effect of Account Deletion: If you choose to delete your main Delta Calendar account, this action will not result in the deletion of the Research Data you previously agreed to share. The de-identified Research Data will be retained for the completion of the study and for any subsequent data retention periods required by the research protocol or law.

Your Rights and Controls

• Access and Portability: You can export a complete copy of your data at any time from the app's settings. The data is provided in a ZIP file containing structured JSON files.
• Editing and Deletion: You have full control to add, edit, or delete any of your entries (events, metrics, etc.) directly within the app at any time.
• Account Deletion: You can permanently delete your Delta Calendar account and all associated server-side data from within the app's settings. This action is irreversible and will remove your synchronized data from our active servers. Please note, this does not apply to data you have consented to share with research studies, as detailed in the "Data Sharing for Research Studies" section above. Such data is retained to ensure research integrity.

Third-Party Services

• Apple (Core Location & WeatherKit): Used for location and weather data as described above.
• Chess.com: Used for fetching ELO ratings if you enable the feature.

Data We Do Not Collect

We do not use third-party analytics, advertising networks, or any other SDKs that track you or collect data from your device for purposes other than the core functionality described in this policy.

Changes to This Policy

We may update this privacy policy as the app evolves. Any changes will be reflected in the "Last updated" date at the top of this page. We encourage you to review this policy periodically.

Contact Us

If you have questions or concerns about this privacy policy, please email us at [email protected].