Last updated: August 29, 2026
Introduction
Welcome to By Day. We respect your privacy and are committed to protecting your personal data. This privacy policy explains how we collect, use, and safeguard your information when you use our web dashboard, mobile apps, and related services.
Information We Collect
Personal Information
When you create an account, we may collect:
- Name and email address (from Sign in with Apple, Google, or email sign-up)
- Account, authentication, and session identifiers
- Profile photo you choose to upload
- Profile information you provide, such as your display name, birthdate, optional biological sex, and focus preferences
Health Data
With your explicit permission, By Day can sync health data from the sources you connect. The categories depend on the source and device:
- Health Connect (Android): sleep sessions and sleep stages. By Day does not request other Health Connect data categories in the current Android app.
- Apple Health (iOS): sleep, steps, activity, exercise, calories, heart rate, heart rate variability, resting heart rate, oxygen saturation, respiratory rate, and wrist temperature.
- Google Health: activity, health metrics, and sleep data that you authorize from your connected Google Account. You can approve all or only some of these categories.
- Oura: the sleep, readiness, and activity data you authorize through your Oura account.
Your health data remains private and health syncing is optional. You can disable health data access at any time through your device settings.
Some health metrics are transmitted to our secured servers so we can compute summaries, trends, and sprint progress that persist across your devices. We do not use health data for advertising, we do not sell it, and we do not share it with third parties other than the infrastructure providers listed below who process it on our behalf. In accordance with Apple's HealthKit requirements, HealthKit data is not used for advertising or other data-mining purposes, and is not shared with third parties for those purposes.
By Day's use of information received from the Google Health API adheres to the Google Health API Developer and User Data Policy, including its Limited Use requirements. Google Health data and data derived from it are used only to provide or improve the user-facing baseline, sprint comparison, progress, and health-data features described in this policy. They are not transferred, sold, or used for advertising, credit decisions, or training a general-purpose AI or machine-learning model.
Community and User-Generated Content
If you use the creator marketplace, we collect the content you create and the actions needed to operate that marketplace, including:
- Creator plans, creator profiles, schedules, testing calls, and published plan editions
- Plans you save or start and qualified feedback you choose to submit
- Blocks and reports you submit
- Private journal entries and task notes you choose to save while following a plan
Creator plans and creator profile information you publish are visible to other users. Drafts remain private until you publish or promote them for testing. Private journal entries and task notes are not shared with creators or published in the marketplace. Creator performance data is shown only as thresholded, aggregated information designed to avoid identifying individual runners.
Subscription Information
Explorer subscriptions purchased in the mobile app are processed directly by Apple's App Store on iPhone or Google Play on Android. By Day receives and stores the store product identifier, transaction or order identifier, purchase token, purchase date, subscription status, and related verification data so we can activate, renew, and restore your subscription. We do not receive or store your payment card or bank account details.
Usage Data
We automatically collect information about how you use the service:
- Features you use and actions you take
- Sprint completion rates and habit tracking progress
- Device information, device identifier, and operating system version
- Crash reports and performance data
If you opt in, Mixpanel processes product analytics such as feature usage and sprint progress under our instructions. Those events can be associated with your By Day account identifier. They are not used for cross-app or cross-website tracking and are not shared with data brokers or advertisers. You can opt out at any time from the Settings screen in the app.
On this website, optional analytics remain off unless you choose Allow analytics. If you allow them, Mixpanel and Meta Pixel process page views, referring domains, campaign parameters, and interactions with key links. We do not send health records, sprint data, or free-form text to these services. Your choice is stored in your browser and can be changed at any time through the Privacy choices link in the site footer. We also respect a supported browser Do Not Track signal by keeping optional analytics off.
Sentry processes crash reports and diagnostics so we can find and fix reliability problems. By Day configures Sentry not to send default personally identifiable information, while allowing technical app, operating system, and device context needed to diagnose a failure.
Third-Party Service Providers
We use the following providers to operate By Day. Each processes data only on our behalf under a data-processing agreement:
- Apple (Sign in with Apple, Apple Health, push notifications, and direct App Store in-app purchases)
- Google (Google Sign-In, Google Health, Health Connect, and direct Google Play purchases on Android)
- Mixpanel (product analytics, opt-in)
- Meta Pixel (website campaign measurement, opt-in)
- Sentry (crash reports and technical diagnostics)
- Oura (health data you choose to connect from your Oura account)
- Our cloud hosting and database providers (application hosting, encrypted data storage)
How We Use Your Information
We use the collected information to:
- Provide and improve the By Day web and mobile experience
- Personalize your health programs and recommendations
- Track your progress and surface relevant patterns
- Send you push notifications (if enabled)
- Respond to your support requests
- Ensure the security and integrity of our services
Data Storage, Retention, and Security
We implement industry-standard security measures to protect your data. All data is encrypted in transit (TLS) and at rest. Access to production systems is restricted to authorized personnel and logged.
We retain your personal data for as long as your account is active. When you delete your account, we delete or anonymize your personal data, creator marketplace content, and health data from our production systems within 30 days, except where we are required to retain specific records to comply with legal obligations, resolve disputes, prevent fraud, or enforce our agreements. This may include limited subscription transaction, accounting, security, or legal records. Encrypted backups are rotated and purged within a further 90 days.
Delete Your Account or Data
To delete your account in the By Day app, open Settings, scroll to the bottom, and choose Delete account. Confirming the request schedules deletion of the account and associated profile, creator marketplace content, health data, sprint history, private journal entries, and task data as described above.
You can archive creator drafts, withdraw eligible creator plans, and delete private journal entries and task notes from the controls provided for that content without deleting your account. You may also request deletion of your account or specific data by emailing privacy@byday.app. Include the email address associated with your By Day account and tell us whether you want to delete the full account or particular data. We may ask you to verify account ownership before we complete the request.
Your Rights and Choices
You have the right to:
- Access and review your personal data
- Delete your account or request deletion of specific data
- Opt out of push notifications
- Disable Apple Health, Google Health, Health Connect, or Oura integration
- Export your data in a portable format
Data Sharing
We do not sell your personal information. We may share anonymized, aggregated findings for research and product analysis. Third-party service providers process data only on our behalf and under confidentiality and data-processing agreements.
Children's Privacy
By Day is not intended for children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal information, please contact us.
Changes to This Policy
We may update this privacy policy from time to time. We will notify you of any significant changes through the service or via email.
Contact Us
If you have questions about this privacy policy or how we handle your data, please contact us at: