Privacy

Due Date Buddy has two parts, and they handle what you type differently.

The quick calculator

The calculator runs entirely in your browser. Due dates, late-fee schedules, and reminder text are computed on your device in plain JavaScript — nothing you enter in the calculator is sent or stored anywhere, and it keeps working offline. When you close the tab, it’s gone.

The chat assistant

When you send a chat message, your message and the conversation so far are sent to this site’s server (hosted on Cloudflare), which forwards them to Anthropic’s Claude API to generate the reply. The math behind every answer is still computed by this site’s own code — the AI is only used to understand your question and phrase the response.

There are no accounts and no database: we don’t store your conversations, and chat history lives only on your device while the page is open. Messages sent to the assistant are handled by Cloudflare and Anthropic under their respective service policies. As with any online chat, don’t include sensitive details you wouldn’t put in an email.

Subscriber sign-in via BizTank

If you open Due Date Buddy from a BizTank subscription, the entry page passes your one-time BizTank sign-in token to this site’s server, which verifies it with BizTank and then discards it — the token itself is never stored or logged. On success we set a single, strictly necessary session cookie (a signed subscriber identifier) so you stay signed in on that device for up to 7 days. It contains no personal details and is not used for tracking. If you never use BizTank entry, no cookie is ever set.

Everything else

No analytics, no tracking pixels, no ads, and no third-party scripts or fonts. The only cookie is the optional subscriber sign-in cookie described above — there are no tracking cookies of any kind. Each page ships a Content-Security-Policy that blocks the browser from connecting to anything except this site’s own endpoints — so there is nowhere else for your data to go.