The short version: Time Transit is designed to work entirely on your device. Your health data never leaves your iPhone. We don't have user accounts, we don't collect email addresses, and we don't sell or share your information. The details below explain exactly what the app accesses and why.
01 — Overview
Time Transit ("the App," "we," "us") is a circadian rhythm adjustment application developed for iOS. This Privacy Policy describes how we handle information in connection with the App. We have designed Time Transit from the ground up with a privacy-first architecture: your personal and health data is processed locally on your device and is never transmitted to our servers or any third-party services for core functionality.
By using Time Transit, you agree to this Privacy Policy. If you do not agree, please discontinue use of the App.
On-Device Processing: All circadian calculations, schedule generation, and protocol personalization happen entirely on your iPhone using Apple's on-device frameworks. We do not operate servers that receive your personal or health data.
02 — Data We Access
Time Transit accesses the following information to provide its core functionality. All of this information remains on your device unless explicitly stated otherwise.
| Data Type | Source | Purpose | Storage |
|---|---|---|---|
| Travel itinerary (departure city, destination, travel dates) |
You enter it manually | Calculate timezone offset and required phase shift | On-device only |
| Sleep data (sleep start/end times) |
Apple HealthKit (with your permission) | Estimate your current circadian phase and chronotype | On-device only |
| Chronotype preference (morning/evening tendency) |
In-app questionnaire | Calibrate your DLMO estimate | On-device only |
| Notification permissions | iOS system | Deliver protocol reminders at the right time | On-device only |
| Local time and timezone | iOS system clock | Schedule notifications relative to your current position | On-device only |
03 — What We Never Collect
We explicitly do not collect, store, transmit, or process the following:
Time Transit does not display advertising. Your data is never sold to or shared with advertising networks, data brokers, or marketing platforms.
04 — Health & Activity Data
Time Transit requests read access to select Apple HealthKit categories to improve the accuracy of your circadian protocol. Specifically, the App may request access to:
You control HealthKit permissions through iOS Settings → Health → Data Access & Devices. Granting these permissions is optional — Time Transit functions with manually entered data if you prefer not to share health data.
Apple's HealthKit Rules Apply: In accordance with Apple's HealthKit guidelines, Time Transit does not share HealthKit data with third parties, does not use HealthKit data for advertising, and does not store HealthKit data outside of the device's secure HealthKit store.
HealthKit data accessed by Time Transit is read at the moment of protocol generation and is not retained in the App's own storage beyond the current session. It is not written to any remote database.
05 — Notifications
Time Transit's core experience is delivered through precisely timed local notifications — alerts that tell you when to seek light, begin darkness, take melatonin, adjust meals, or perform other protocol actions.
These notifications are local notifications, meaning they are scheduled entirely on your device by the App itself. They do not pass through Apple's Push Notification Service (APNs) and are not triggered by or reported to our servers. No notification content is transmitted off your device.
You can manage notification permissions at any time in iOS Settings → Notifications → Time Transit. Disabling notifications significantly reduces the App's usefulness, as timely protocol adherence is central to circadian adjustment.
06 — Analytics & Crash Reporting
Time Transit uses Apple's built-in crash reporting and App Store analytics exclusively. These are provided by Apple and governed by Apple's own privacy policy. We do not integrate third-party analytics SDKs (such as Amplitude, Mixpanel, Firebase Analytics, or similar).
Crash reports submitted through Apple's system are anonymized and aggregated. They may contain device model, iOS version, and a stack trace of the crash — no personally identifiable information, health data, or itinerary details are included.
You can opt out of sharing diagnostic data with developers through iOS Settings → Privacy & Security → Analytics & Improvements.
07 — Third Parties
Time Transit's core functionality does not rely on any third-party services, SDKs, or APIs beyond Apple's native frameworks (HealthKit, UserNotifications, SwiftData, CoreLocation for timezone only).
We use the following Apple-native technologies:
This privacy policy does not govern Apple's services. Please review Apple's Privacy Policy at apple.com/legal/privacy for information on how Apple handles data.
08 — Children's Privacy
Time Transit is not directed at children under the age of 13, and we do not knowingly collect personal information from children under 13. The App's content and purpose — jet lag adjustment for travelers — is intended for adult users.
If you are a parent or guardian and believe your child has used the App in a way that has resulted in data collection, please contact us at the address below and we will take appropriate steps to address the situation.
09 — Your Rights
Because Time Transit does not collect or store your personal data on remote servers, the conventional data subject rights under regulations such as GDPR and CCPA operate primarily through your device controls:
If you have questions about data rights that are not addressed by the above device controls, please contact us at the address in the Contact section below.
10 — Policy Changes
We may update this Privacy Policy from time to time to reflect changes in our practices, the App's features, or applicable law. When we make material changes, we will update the "Effective Date" at the top of this document and, where appropriate, notify users through an in-app notice.
Continued use of Time Transit after a policy update constitutes your acceptance of the revised terms. We encourage you to review this policy periodically.
11 — Contact
If you have questions, concerns, or requests regarding this Privacy Policy or Time Transit's data practices, please contact us:
Time Transit Support
Email: privacy@timetransitapp.com
We aim to respond to all privacy-related inquiries within 5 business days.
For general support questions unrelated to privacy, please visit our Support page.