Legal · Data Privacy
Privacy Policy.
Last updated · May 2026
The short version.
Your conversations are stored securely on our servers and processed by OpenAI to generate responses. We don’t sell your data or use it for advertising. This page explains exactly how it works — required by law, but written in plain language.
I · Controller
The controller responsible for data processing on this website is:
Kolja Blauhut (private individual)
Email: koljablauhut@gmail.com
Kolja Blauhut (private individual)
Email: koljablauhut@gmail.com
II · What Data We Collect
App — conversations & goals: When you use Dayarc, your chat messages and goals are sent to and stored on our backend (hosted on Vercel, database hosted by Neon). This serves as your data backup and enables AI-powered responses. The legal basis is Art. 6(1)(b) GDPR — processing necessary to provide the service you requested.
AI processing: Your conversation content is sent to OpenAI to generate responses. OpenAI processes this data as a data processor on our behalf under a data processing agreement. OpenAI does not use your data to train its models by default. See OpenAI’s privacy policy for details.
This website: When you visit this website, Vercel processes standard server log data — your IP address, browser type, referring URL, and page requested — for a limited time to ensure security and availability. This is a legitimate interest under Art. 6(1)(f) GDPR.
Analytics: We use two analytics tools on this website. Vercel Analytics collects aggregate traffic patterns (pages viewed, device types, countries) without cookies and without tracking individual users across sessions. PostHog collects anonymised usage events (page views, button clicks) to help us understand how visitors use the site. PostHog uses a first-party cookie to distinguish sessions; it does not use that data for advertising. The legal basis for both is our legitimate interest in improving the website under Art. 6(1)(f) GDPR.
AI processing: Your conversation content is sent to OpenAI to generate responses. OpenAI processes this data as a data processor on our behalf under a data processing agreement. OpenAI does not use your data to train its models by default. See OpenAI’s privacy policy for details.
This website: When you visit this website, Vercel processes standard server log data — your IP address, browser type, referring URL, and page requested — for a limited time to ensure security and availability. This is a legitimate interest under Art. 6(1)(f) GDPR.
Analytics: We use two analytics tools on this website. Vercel Analytics collects aggregate traffic patterns (pages viewed, device types, countries) without cookies and without tracking individual users across sessions. PostHog collects anonymised usage events (page views, button clicks) to help us understand how visitors use the site. PostHog uses a first-party cookie to distinguish sessions; it does not use that data for advertising. The legal basis for both is our legitimate interest in improving the website under Art. 6(1)(f) GDPR.
III · Cookies
This website uses one first-party cookie set by PostHog (
ph_*) to distinguish sessions and measure returning visits. It contains a random identifier and no personal data. It is not used for advertising or shared with third parties for targeting purposes. Vercel Analytics operates without any cookies. No advertising cookies are used on this site.IV · Third-Party Services
Vercel (hosting & analytics): Our website and backend API are hosted by Vercel Inc., 340 Pine Street, Suite 701, San Francisco, CA 94104, USA. Vercel’s privacy policy applies: vercel.com/legal/privacy-policy.
Neon (database): Your conversations and goals are stored in a PostgreSQL database hosted by Neon Inc., 225 Bush Street, Suite 300, San Francisco, CA 94104, USA. Neon’s privacy policy applies: neon.tech/privacy-policy.
OpenAI (AI processing): Conversation content is sent to OpenAI, L.L.C., 3180 18th Street, San Francisco, CA 94110, USA, to generate AI responses. OpenAI acts as a data processor under a data processing agreement and does not use your data to train its models by default. OpenAI’s privacy policy applies: openai.com/policies/privacy-policy.
PostHog (web analytics): We use PostHog to collect anonymised usage events on this website. PostHog Inc., 965 Mission Street, Suite 175, San Francisco, CA 94103, USA processes this data as a data processor on our behalf. Data is stored in the EU (PostHog Cloud EU). PostHog does not use your data for advertising. PostHog’s privacy policy applies: posthog.com/privacy.
Apple App Store: The Dayarc iOS app is distributed through the Apple App Store. Apple’s privacy practices apply to that transaction. We receive only anonymised download statistics.
Neon (database): Your conversations and goals are stored in a PostgreSQL database hosted by Neon Inc., 225 Bush Street, Suite 300, San Francisco, CA 94104, USA. Neon’s privacy policy applies: neon.tech/privacy-policy.
OpenAI (AI processing): Conversation content is sent to OpenAI, L.L.C., 3180 18th Street, San Francisco, CA 94110, USA, to generate AI responses. OpenAI acts as a data processor under a data processing agreement and does not use your data to train its models by default. OpenAI’s privacy policy applies: openai.com/policies/privacy-policy.
PostHog (web analytics): We use PostHog to collect anonymised usage events on this website. PostHog Inc., 965 Mission Street, Suite 175, San Francisco, CA 94103, USA processes this data as a data processor on our behalf. Data is stored in the EU (PostHog Cloud EU). PostHog does not use your data for advertising. PostHog’s privacy policy applies: posthog.com/privacy.
Apple App Store: The Dayarc iOS app is distributed through the Apple App Store. Apple’s privacy practices apply to that transaction. We receive only anonymised download statistics.
V · Your Rights (GDPR)
Under the GDPR you have the right to:
Access
Request a copy of any personal data we hold about you.
Rectification
Ask us to correct inaccurate data.
Erasure
Ask us to delete your data where there is no compelling reason for its continued processing.
Restriction
Ask us to restrict how we use your data.
Portability
Receive your data in a structured, machine-readable format.
Objection
Object to processing based on legitimate interest.
To exercise any of these rights, contact us at koljablauhut@gmail.com. You also have the right to lodge a complaint with your local data protection authority.
VI · Data Retention
Your conversations and goals are stored on our servers for as long as you use the app. You can request deletion at any time by contacting us — we will permanently delete your data from our database within 30 days.
Server log data is retained for up to 30 days and then automatically deleted. Anonymised analytics aggregates contain no personal data and are retained indefinitely.
Server log data is retained for up to 30 days and then automatically deleted. Anonymised analytics aggregates contain no personal data and are retained indefinitely.
VII · Changes to This Policy
We may update this policy occasionally. When we do, we’ll update the “Last updated” date at the top of this page. Significant changes will be noted in the app release notes. Questions? Write to koljablauhut@gmail.com.