There is no clock in the pattern
The QR specification does not include an expiry date. A code made in 2014 still scans. What changes is the thing the text points at.
If the text is https://your-site.example/pricing and you later delete that page, the code still scans and the browser shows a missing page. The code did not expire. The page did.
If the text is a vendor's short link, the vendor can retire that link. The pattern is intact and the destination is gone. That is the failure people describe as a QR code expiring.
How to keep a code working
Put the final https address in the pattern. Use a domain you intend to keep. Leave the page up, or redirect that exact path from your own site if you move it.
Download the SVG or PNG and keep the file. You do not need to come back to Still to renew it.
- Prefer a path you control, such as your own domain.
- Avoid a free short link you do not operate.
- Test the printed code with a phone before you order a large run.