Privacy Policy

Effective date: 19 November 2026 · Version: 1.0.0

This is an English translation provided for convenience. The Vietnamese version is the official text; if the two differ, the Vietnamese version applies. Button and menu names are given in English; the website and the app show them in Vietnamese.

This page explains what the Ngày Gia Tiên website (ancestordays.com) and the Ngày Gia Tiên Android app do with your data. In short:

• Without signing in: the list of relatives you enter stays only in your browser; we do not receive or store it.
• When you sign in or create a calendar subscription: the list is stored on Google Firebase servers to sync it between your devices and so that your calendar app can read it. You are asked for consent first, and you can delete it at any time.
• We do not sell or rent your data and do not use it for advertising.

1. Who is responsible

The website and the Android app are operated by an individual: Nguyễn Minh An (“we”). Privacy contact: [email protected].

2. Using it without an account: your data stays on your device

When you add a person (name, relationship, date of death, options for calculating the death anniversary) and reminder settings without signing in, the website stores this information in the browser’s storage (localStorage) on the device you are using.

• That data is not sent to our servers and we cannot see it.
• You can edit or delete each person at any time. The “Delete all data” button removes everything from the browser.
• If you clear your browser data, use private browsing or change devices, the list is gone. Use “Download backup” to keep a copy on your device.
• Protecting your device and browser (device password, malware, other people using the same device) is outside our control.
• The website has no field for the cause of death, health information, photos, dates of birth or free-form notes.

3. Accounts and the synced list

Accounts

There are two kinds of account, both managed by Google’s Firebase Authentication service:

• The display name and profile photo are only used to show in the corner of the page while you are signed in. The email lets you recognise your account, and lets us reply when you contact us from that address.
• We do not receive your Google password. Sign-in is handled by Google.
• When you sign in for the first time on a device that already has a list, the people in that list are moved into the account (or merged with the existing list, if you choose “Merge”), and then removed from the browser storage.

The synced list

When you are signed in with Google, your list of relatives and your settings are stored in the Google Cloud Firestore database in Singapore:

• For each person: name, relationship (if you enter it), lunar date of death, options for calculating the death anniversary, and the times it was created and edited.
• Settings: how many days ahead to remind you, the holidays you chose, and the number of people in the list (to apply the limit of your plan).
• The names of the groups you create (for example “Chi Hai”, “Nhà bác Cả”) and which group each person belongs to.
• When you delete a person, that person’s record is kept with the name and dates removed for up to 90 days, so that your other devices know to delete it too; after that the record is removed completely.

Only you (when signed in) can read and edit your list (a family list: its members, section 3); the database security rules block every other account. The operator has technical administrator access to the database and accesses your data only when needed to fix a problem, when you ask for support, or when required by law.

Family list

With Premium, you can create a family list and invite relatives to view and edit it together:

• We store the account ID, role and display name chosen by each member in the family list, together with the people in the list and pending invitations.
• Every member can see the whole family list and each other’s display names. The person who created the list is responsible for the people added to it.
• A member who leaves the list loses access. Deleting the family list deletes its data.
• To notify the family when the list changes, the Android app stores a notification token (Firebase Cloud Messaging) for your device.

4. Calendar subscription, downloaded files and share links

Calendar subscription (updates automatically)

When you click “Create link” for a calendar subscription (webcal), you are asked for consent for this specifically. Then:

• The website creates a calendar file containing the names and dates of the people in the list (and the holidays you chose), stored on Google’s Firebase Storage in Singapore. With an anonymous account, the file contains at most the first 5 people in the list on the device.
• The file has a secret, hard-to-guess address. Anyone with this address can see the names and dates in the calendar, without signing in. The calendar app you subscribe with (Google Calendar, Apple Calendar, Outlook…) reads the file periodically and keeps a copy under that provider’s policy.
• The file is updated when you edit the list; calendar apps may keep the old copy for about 6 hours or longer, depending on the app.
• “Change link” stops the old address from working immediately. Deleting your account also deletes the calendar file.
• With an anonymous account, this is the first time the list (up to 5 people) leaves your device. The original list still stays only in the browser.

Files you download and share links

• Calendar files (.ics) and backup files are created on your device when you click download. Once downloaded, the file is yours to manage. If you import an .ics file into a calendar app, the data in it is subject to that app provider’s policy.
• When you create a link to share a list, the names and dates of the selected people are compressed into the part of the link after the # sign. Browsers do not send this part to the server, so we do not receive it. Anyone with the link can see the list, and chat apps, email and browser history may keep the link; send it only to people you trust. A recipient who clicks “Import” gets a separate copy, not connected to your list.

5. Trial, paid plans and the limit on people

• Trial: the first time you sign in with Google, the account gets a 30-day Premium trial. We store the time the trial started (server time) together with a hash of the Google account (without email or name), so that each Google account gets the trial only once, even after deleting the account and signing in again. You consent to keeping this hash when you first sign in (section 7).
• Buying a plan: plans are bought in the Android app and paid through Google Play. We do not receive or store card or payment account details; Google Play holds them. We store: your current plan, the maximum number of people, the expiry date, the date of first purchase, and the purchase records (product, status, expiry date, the Google Play purchase token hashed so that it cannot be reversed, and the Google Play order ID). This data is used to unlock features on all your devices, restore purchases and handle refunds.
• When a trial or plan ends and the list is over the limit: for the first 30 days nothing changes; after that the list is locked (view, delete, download a backup) and the calendar subscription keeps only the people you choose to keep, until you buy again; we do not delete anyone because a plan ended (Terms of Use, section 4). For this we store a record of the expiry date, the lock date and when notices were sent; the record is deleted when the list is back within the limit.
• Notice emails: when the plan expires and 7 days before the list is locked, we send an email to the Google address of the account. These are notices about a service you use, not advertising, and are not sent to members of a family list.
• Support for the Dòng họ (Clan) plans: if you email us a list to get help preparing an import file, we use it only to make a CSV file for you to import yourself, do not write it into your account ourselves, and delete the email and its attachments within 7 days after the support is finished.

6. Android app

• Death anniversary reminders are notifications scheduled on the phone itself; they do not go through a server.
• “Add to calendar” for a single date opens the phone’s calendar app so you can save it yourself; the app does not ask for permission to read your calendar, contacts or location.
• Bug reports: the app does not send crash reports or usage data on its own. When you tap “Report a problem, send feedback”, the app opens an email to [email protected] with the app version, device model and Android version filled in; you review it and decide whether to send it.
• Without signing in, the list in the app stays only on the phone, as in the browser (section 2).

7. Consent, abuse prevention and access logs

Recording your consent

Before saving the list to an account, you are asked to confirm that:

• you are the spouse, child, parent or another relative of the deceased (or have the consent of those people) and enter only the information needed to remember the death anniversary, because information about deceased people is also personal data protected by law;
• you are 16 or older and agree to this policy, including keeping a hash of the Google account after the account is deleted so that each account gets the trial only once (section 5).

We store the version of the text you agreed to and the time of consent (and the time you consented to creating a calendar subscription) in the account, as evidence. If you do not agree, you can still use the service as a guest; your data stays on your device.

Abuse prevention

To block automated requests that do not come from the real website, the site uses Firebase App Check with Google Cloud Fraud Defense (formerly reCAPTCHA Enterprise). Fraud Defense collects technical information about the browser and device (for example browser configuration and how you interact with the page) and sends it to Google for assessment, under Google’s Privacy Policy and Terms. We receive only the result (“valid or not”), not that information.

Access logs and usage counts

Like every website, the content delivery service (Amazon CloudFront, from Amazon Web Services) logs each time a page is loaded:

• Logs are kept in private AWS storage in Singapore, accessible only to the operator, and are deleted automatically after 120 days.
• To learn which features are useful, after some actions (for example saving a person, downloading an .ics file, creating a share link, signing in) the website loads an empty file named after the action, for example /e/add-person. This request contains only the name of the action: no names, dates, list content, account ID or email. It is part of the access log and follows the same retention and deletion rules.
• Reports from the logs contain only totals. We do not use the logs to build a profile of you and do not link them to accounts.

8. Who receives data and where it is stored

We use the following service providers. They process data on our behalf, under their data processing terms, and may not use the data for their own purposes:

This means your data is transferred abroad (to Singapore and the countries where the providers above have servers). Data is encrypted in transit (HTTPS) and at rest on the providers’ infrastructure. Apart from these providers, we provide data to competent authorities only when required by law.

9. Retention, your rights and how to delete

You have the right to be informed, to access, correct and delete, to restrict and object to processing, to withdraw consent and to obtain your data:

• Access, correct, obtain your data: directly on the website; “Download backup” gives you the whole list as a JSON file.
• Withdraw consent to the calendar subscription: “Change link” or delete the account.
• Delete the account (Account › “Delete account”): the website invites you to download a backup first, then deletes in turn the calendar subscription file, the whole list and settings, and finally the account; plan data and the expiry record are deleted automatically right after. After the account is deleted, we keep a hash of the Google account and the trial start date, so that each account gets the trial only once and to keep a paid plan. Deleting the account automatically cancels the renewal of yearly plans in Google Play; signing in again with the same Google account lets a yearly plan continue until the end of the paid period and a lifetime plan continue, but the deleted list cannot be restored (Terms of Use, section 4). If you created a family list, you need to hand it over to another member or delete it first. Deletion happens immediately; if a step fails (for example the connection drops), the page says the deletion is not finished and tries again the next time you open it. Your other devices sign out and delete their local copy.
• Other requests (for example about access logs): email the address in section 1. For logs, include the time of access and the IP address (if known), because logs contain no names. We reply within the time limits set by law.
• You can lodge a complaint with the state authority for personal data protection (the Ministry of Public Security).

Legal basis (Law on Personal Data Protection No. 91/2025/QH15, Decree 356/2025/NĐ-CP): account data, the synced list, the calendar subscription and the trial hash are processed on the basis of your consent (section 7); plan data (including keeping a paid plan under the hash of the Google account after you delete the account), plan notice emails, access logs and abuse prevention checks are processed to perform the contract with you, that is, to provide the service you use or have bought safely; purchase records are kept to meet legal obligations under accounting and tax law.

10. Security, incidents, children and changes to this policy

• The website runs only over HTTPS. The database security rules let each account read and write only its own data. The operator’s administrator accounts use two-step verification. Lists of relatives are not written to logs.
• If an incident occurs that may affect you, we notify the competent authority and the people affected within the time limits set by law.
• Risks you should know: anyone with a share link or calendar subscription address can see the names and dates in it, and chat, email and calendar apps may keep them; the list in the browser is lost when browser data is cleared; people who share a device with you can see the list on it. Use “Change link” when a calendar address is exposed and “Download backup” to keep a copy.
• The website and the app are not directed at people under 16.
• The website does not use advertising cookies or third-party analytics tools. Firebase keeps the sign-in session in the browser’s storage; Google’s Fraud Defense may set its own cookies for abuse prevention (section 7).
• Important changes are announced on the website at least 15 days before they take effect. If a change extends the purposes of processing, we ask for your consent again before processing for the new purpose. The version and effective date at the top of the page tell you which version you are reading.

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