Privacy Policy

Calendar add-ons by UsefulAddons, Switzerland. Covers Weather Calendar, Weather Calendar Pro, Weather Calendar Ultra, Pollen Calendar, Daily Horoscope Calendar, Horoscope Calendar Pro and AI Day Planner. Last updated: October 2026.

These add-ons put useful information (weather, pollen, horoscopes, AI-planned tasks) into your own Google Calendar. We collect as little as possible, and we never sell your data or show ads.

Google API Services User Data Policy (Limited Use)

The use of raw or derived user data received from Google APIs, including Google Workspace APIs, will adhere to the Google API Services User Data Policy, including the Limited Use requirements. We use Google user data only to provide and improve the user-facing features of our add-ons, we never transfer it except as needed to provide those features (to the processors named below), never sell it, never use it for advertising, never allow humans to read it except with your consent or as required for security or by law, and never use it - raw, aggregated, anonymized or derived - to develop, improve or train generalized or non-personalized AI/ML models.

How we use Google user data

• Your Google account email address is used only to check your license or free trial and the add-on's fair-use limits, and to answer you when you send us feedback.
• Google Calendar access is used only to create, update and remove the add-on's own events in your calendar; the AI Day Planner also reads the busy times and event titles of the one day you ask it to plan, so it can schedule around them.
• Your language, country and timezone are used only to show dates and times correctly.
• Google user data is used for nothing else: not for advertising, marketing, profiling, resale or training AI models.

What we process

• Your Google account email address. It is the key we use to look up your purchase: after you pay, Stripe tells us the email you used at checkout and we store a small license record (email, subscription status and expiry date) in a Firebase database hosted in the EU (europe-west1). That record is what unlocks the add-on.
• Free trials. Pollen Calendar, Daily Horoscope Calendar, Horoscope Calendar Pro and AI Day Planner include a 7-day free trial, no card required; each add-on notes the date your trial started in your own add-on settings (Apps Script user properties in your Google account). For Daily Horoscope Calendar, Horoscope Calendar Pro and AI Day Planner, whose content comes from our server, the first time you use the add-on's online features without a license our server also records the add-on and the date and time of that first use in Cloudflare Workers KV, under a one-way hash of your email address (truncated SHA-256) - never the address itself - so the 7-day trial cannot be restarted. This record expires automatically after about 13 months (400 days). Pollen Calendar's trial is tracked only in your add-on settings, never on our servers.
• The location you choose (weather and pollen add-ons). It is sent to the respective forecast service (Open-Meteo, OpenWeather, or the Google Pollen API) to fetch your forecast. Responses may be cached briefly on a coarse geographic grid to reduce API calls; we do not store your location per user on our servers.
• Calendar events. The add-ons create and update their own marked events in your Google Calendar, which stays entirely in your Google account - we do not copy your calendar to our servers. The AI Day Planner additionally reads the busy times and event titles of the one day you ask it to plan, so it can schedule around your commitments.
• Text you submit for AI features. For AI-generated content (horoscopes, day plans), the needed inputs - your zodiac sign, birth date and optional birth time (horoscope products), or your to-do text and that day's busy slots including their event titles (AI Day Planner) - are sent transiently through our server to our AI provider (Anthropic) to generate the content, then returned to your add-on. We do not keep this content on our servers beyond short-lived caches, and per the provider's policy it is not used to train AI models. The AI Day Planner also offers a no-AI planning mode (built-in rules) in which none of this is sent anywhere.
• Personalization (AI Day Planner). To plan better for you over time, the add-on keeps a small summary of your own past plans - your usual start time and duration per kind of task, how many plans you have made, and the to-dos that did not fit last time - stored only in your Google account (Apps Script user properties), never on our servers. When you choose "Plan with AI", your usual start times and durations are sent along with that request as planning hints and are not stored. You can see this summary and erase it at any time under the add-on's Data & privacy card ("Forget what you learned").
• Plan ratings (AI Day Planner). After each plan you can tap 👍 or 👎. This sends only the rating and the planning mode (AI or built-in rules) to our server, where they are counted per day in aggregate to improve the planner - no plan content, no calendar data and no email.
• Feedback you send. The in-app feedback form sends your message and your email address to our server. We use them only to answer you and to fix the issue; entries expire automatically about 90 days after they are received, and you can ask us to delete yours sooner at any time.
• Payments. All payments are processed by Stripe. We never see or store your card number; we only receive your checkout email and subscription status.

What we do not do

• No advertising, no trackers, no analytics profiles.
• No sale or sharing of personal data with third parties beyond the processors named above (Google, Stripe, Firebase, Cloudflare (our server hosting and storage), the forecast APIs, Anthropic), each used only to provide the service.
• No training of AI/ML models on your data: we do not retain user data obtained through Google Workspace APIs to develop, improve, or train non-personalized AI and/or ML models; the only personalization is the per-user summary described above, kept in your own Google account.

How we protect your data

• Encryption in transit. Every connection between the add-ons, our server (Cloudflare Workers), the license database (Firebase Realtime Database), Stripe, the forecast and pollen services and our AI provider (Anthropic) uses HTTPS (TLS); the add-ons can only connect to an allowlist of https:// addresses.
• Encryption at rest. License records are stored in Firebase Realtime Database, which Google encrypts at rest. Our server stores feedback messages, free-trial records, and its short-lived counters and caches in Cloudflare Workers KV, which encrypts stored values at rest.
• Access control. Our service credentials (forecast, pollen and AI-provider API keys, database credentials, webhook secrets) are kept in server-side secret storage (encrypted Cloudflare Worker secrets and Apps Script script properties), never in source code or in the add-on's interface. For Pollen Calendar, Daily Horoscope Calendar, Horoscope Calendar Pro and AI Day Planner, the license database's security rules deny all direct access, so only our server and the add-ons' server-side code, which hold the database credential, can read or write it; our server accepts requests only from these add-ons (authenticated with a secret client key) or with a personal AI-access key, and their payment events only with a valid Stripe signature. Administrative access is limited to the developer.
• Data minimization. The calendar data the AI Day Planner reads (busy times and event titles of the one day you plan) is used only for that request: our server processes it in memory and never stores it or writes it to logs. Personalization stays in your own Google account (Apps Script user properties). Email addresses are masked in our server's application logs.
• Retention limits. Feedback expires automatically about 90 days after it is received and daily fair-use counters after about 26 hours. Free-trial records (the add-on, a hashed email address and the date of first use) expire automatically after about 13 months (400 days). Cached content expires automatically too: forecasts and horoscope readings cached by the add-ons after at most 6 hours, pollen forecasts cached on our server after 6 hours, AI-access key lookups after at most 5 minutes, and the daily horoscope text cached on our server (the same for everyone with that sign, no personal data) after at most 4 days. License records are kept as described under "Data retention and deletion" below.
• Payments. Card data is handled only by Stripe, a PCI DSS Level 1 certified payment provider; we never see or store card numbers.
• Incidents. If we become aware of a security incident affecting your data, we will notify affected users and the competent authorities as required by applicable law (the Swiss Federal Act on Data Protection and, where applicable, the GDPR).

Data retention and deletion

License records are kept while your subscription (plus its grace period) is active; after it ends we keep the purchase record (email and dates) only to meet our accounting and legal obligations. Daily fair-use counters on our server are keyed by your email address and expire automatically after about 26 hours. Free-trial records on our server are keyed by a one-way hash of your email address, never the address itself, and expire automatically after about 13 months (400 days). You can ask us to delete your data at any time by emailing work@louissch.com - we will remove your license record and any related data we hold. Events the add-ons created in your calendar are under your control and can be deleted by you at any time (uninstalling an add-on stops all processing).

Contact and governing law

Data controller: Louis Scheibli (UsefulAddons), Switzerland. Contact: work@louissch.com. This policy is governed by Swiss law. If we change it, the new version will be published at this URL with an updated date.