What we collect and why
To provide the service, we need to access some information. We only ask for what is necessary to block out your busy time.
- Account info: your name and email.
- Calendar data: we read event start and end times and your busy or free status. We keep each event title only inside an encoded change fingerprint, which we compare on each sync to notice edits. It is never copied to another calendar. We do not store descriptions, attendees, locations or meeting links.
- OAuth tokens: keys that let Caltsu reach your Google and Microsoft calendar accounts. The sync engine stores its copy encrypted. The sign-in library keeps a second copy without that extra encryption, and deletes it when you disconnect the account. We never see your password.
- Usage data: sync logs, error reports and product analytics that help us fix bugs and improve the service.
How we use your data
Your data has one job here: to power the calendar sync you signed up for.
- To sync calendars: we read event times from one calendar and create simple "Busy" blocks on your others. No details are ever copied over.
- To keep things running: we use usage data to monitor for problems and improve performance.
- To help you: if you run into trouble, our support team may need to look at your sync logs to find out what is wrong.
A note on Google data. Our use of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements. We do not use it for advertising, AI training or anything other than syncing your calendar.
Who we share data with
We do not sell your data. We only share it with the essential partners who help us run Caltsu.
- Calendar providers: we have to talk to Google and Microsoft to sync your calendars.
- Infrastructure partners: we use Vercel for hosting, Neon for the database (Frankfurt), Stripe for payments, Inngest for background jobs, Resend for email and PostHog for product analytics. PostHog processes data in the United States. The security page lists what each one receives.
- When legally required: if we are required by law, we may have to disclose user data.
Your rights and data deletion
- Access or correct: you can see and update your account info in your dashboard settings.
- Disconnect: you can disconnect any calendar account at any time.
- Delete everything: you can delete your account from your settings page. This removes the Busy blocks Caltsu created, cancels your subscription and anonymizes your account. It cannot be undone. Sync logs are kept until you ask us to erase them at the address below.
For any data requests, email us at the address below.
Contact
If you have any questions about this policy, write to privacy@caltsu.com. Security questions can go to support@caltsu.com, and the security page describes our data handling in technical detail.
Data controller: DataDux Oy (Business ID: 3427414-9), Huopalahdentie 24, 00350 Helsinki, Finland.