Privacy Policy for Lịch Tranh

Last updated: August 29, 2026

This Privacy Policy explains how HuuMy Organization (“we”, “us”, or “our”) handles information when you use the Lịch Tranh mobile application (the “App”).

Information the App does not require

The App does not require an account or sign-in. Some optional features, such as Tử vi profiles, allow you to enter a display name and birth information. We do not require you to provide an email address, phone number, home address, contacts, photos, microphone access, or payment card details.

The App does not upload your calendar notes or personal preferences to an App-owned account. The calendar and lunar-date calculations are provided locally on your device.

Information stored on your device

The App stores information locally to provide its features, including:

• language and display preferences;
• notes attached to calendar dates;
• calendar events and local reminder settings;
• optional Tử vi profiles, which may include a display name, birth date, birth time, gender, lunar-calendar details, and relationship information entered by you;
• optional Tử vi chart history, when you explicitly enable chart-history storage;
• selected/default background settings;
• the IDs of selected or downloaded background packs;
• downloaded background-pack images and manifests in the App’s private support storage;
• an optional selected location (coordinates and a nearby place label) used for local sunrise and sunset calculations; and
• a local record of the Premium entitlement and purchase state.

This information is used to operate the App and is kept on your device unless a feature specifically sends information to a third-party service as described below. The App does not upload your profiles, notes, events, or chart history to an App-owned account or server. You can remove local App data by deleting it in the App where available, clearing the App’s storage, or uninstalling the App. Downloaded packs may also be removed by the App as part of normal pack management.

When you request a backup, calendar image, or Tử vi chart export, the App prepares the file locally and passes it to the operating system’s share or file-picker flow. The destination you choose may receive the exported information. The App does not upload these exports to an App-owned server.

Background-pack service

The App’s default configuration requests background-pack catalogs and image files from packs.giavangvn.vn, operated for the App. These requests can include the requested catalog or image URL and normal technical information such as IP address, request time, device/network information, and user-agent information handled by the hosting infrastructure.

The service provides downloadable artwork and does not receive your calendar notes, events, Tử vi profiles, chart history, purchase card details, or a personal account profile from the App. Downloaded images are stored locally so they can be used offline.

Optional location access

The App uses Ho Chi Minh City as its default location and does not request location access at first launch. If you tap the location edit button in the solar-information card, the App may ask for foreground location permission. If permission is granted, the App uses the current coordinates to calculate sunrise and sunset times and may ask the operating system to resolve a nearby place name for display.

The selected coordinates and place label are stored locally on your device so the App can remember the chosen location. The App does not send this location to its background-pack service or to an App-owned account. You can deny or revoke location permission using the operating-system controls; the App will then keep using the previous location or the Ho Chi Minh City default.

When you use the weather feature, the selected coordinates are sent to api.open-meteo.com to retrieve a forecast and to geocoding-api.open-meteo.com when you search for a place. These services can receive the request URL, IP address, request time, device/network information, and user-agent information through their hosting infrastructure. Open-Meteo’s terms and privacy information are available at open-meteo.com/en/terms. The weather feature does not send your calendar notes, events, Tử vi profiles, chart history, or account information.

Optional Google Calendar connection

If you choose to connect a Google account, the App uses Google Sign-In to request read-only access to Google Calendar. The App requests the calendar.readonly permission so it can retrieve the calendars you select and display their events together with Vietnamese lunar dates. The App does not create, edit, delete, or share Google Calendar events.

The App receives and may store a local cache containing the Google account email, calendar names, event titles, event dates and times, and source links. This cache is kept in the App’s private storage to show the last synchronized results and is not uploaded to an App-owned server. You can disconnect Google Calendar from the App, which removes the cached Google Calendar snapshot; you can also revoke the App’s access from your Google Account settings. Google may process authentication and Calendar data under Google’s Privacy Policy.

Advertising

The App uses Google Mobile Ads to display banner advertisements on supported mobile platforms. Depending on platform, region, consent choices, and Google’s services, Google and its advertising partners may process information such as IP address, approximate location inferred from IP, advertising or app identifiers, ad requests, ad interactions, and diagnostic/performance information for advertising delivery, measurement, fraud prevention, and service operation.

Google’s privacy information is available at policies.google.com/privacy. You can also use the privacy and advertising controls provided by your device and the applicable app store. The App does not receive your payment card number from the advertising SDK.

The App uses Google User Messaging Platform (UMP) to request and store advertising consent where required and provides an in-app advertising privacy-options entry point. On iOS, the App requests Apple’s App Tracking Transparency permission when the system status is not yet determined, before initializing Google Mobile Ads. If you allow tracking, Google Mobile Ads and its advertising partners may use the device’s advertising identifier (IDFA) for personalized advertising and advertising measurement, subject to applicable consent choices. If you deny or do not grant ATT, the App continues to request ads but the Google Mobile Ads Flutter plugin does not send IDFA in the ad request.

Premium purchases

The App offers a one-time Premium product. Apple App Store and Google Play process purchases through your store account and their own payment, privacy, and refund systems. The App receives purchase status so it can unlock Premium features and stores a local entitlement record. We do not receive or store your payment card number or other payment credentials. Restoring or refunding a purchase is handled by the relevant store.

Information the App does not collect

The App does not request contacts, camera, microphone, or background location access. Precise foreground location is optional and is requested only after you choose to edit the solar-information location. The App does not operate its own analytics account, cross-app tracking system, cloud sync for notes, profiles, events, or chart history, or personal advertising profile; Google Mobile Ads may process advertising data as described above and in Google’s privacy policy.

Third-party SDKs and hosting providers may process technical information needed to deliver ads, purchases, network requests, security, and diagnostics as described in their own policies.

How information is used

Information handled by the App is used to:

• calculate and display Vietnamese calendar and lunar-date information;
• calculate local sunrise and sunset times when an optional location is selected;
• retrieve weather forecasts and place-search results for the selected location;
• retrieve and display Google Calendar events when you explicitly connect a Google account;
• save notes, events, Tử vi profiles, optional chart history, preferences, and selected backgrounds locally;
• retrieve and download optional background packs;
• schedule local reminders when you enable them;
• display and measure advertisements;
• process and restore Premium entitlement through Apple or Google; and
• maintain the reliability and security of the App and its background service.

We do not sell personal information and do not use your calendar notes, events, profiles, or chart history to create an account profile.

Retention and deletion

Local notes, events, profiles, optional chart history, preferences, entitlement records, and downloaded artwork remain until you delete them through available App or device controls, clear the App’s storage, or uninstall the App. Local reminders are removed when their events are deleted or reminders are disabled. Exported files remain wherever you choose to save or share them. Store purchase records remain subject to Apple’s or Google’s systems and policies. Hosting, advertising, weather, geocoding, and store providers may retain technical or transaction records under their own policies and legal obligations.

Security

The App uses secure network connections for its hosted background service where available. No Internet transmission or electronic storage method can be guaranteed to be completely secure.

Children’s privacy

The App is not directed to children under 13, and we do not knowingly collect personal information from children. The App does not require an account or upload calendar notes to us.

Changes to this Policy

We may update this Policy when the App’s data practices or applicable requirements change. The updated version will be posted at the hosted policy URL with a new “Last updated” date.

Contact us

Questions about this Policy or the App’s privacy practices can be sent to hhmy1995@gmail.com.