Privacy Policy

Last updated: October 7, 2026.

Calculator data

HowLongKit's launch-version calculators run locally in your browser. Dates you enter are not sent to a HowLongKit server.

Theme preference

Your browser's local storage remembers whether you selected light or dark mode. This preference remains on your device unless you clear browser data.

Analytics and advertising

This launch package does not include third-party analytics or advertising code. If those services are added, this policy will be updated to explain the providers, technologies used and visitor choices.

Future advertising cookies

If Google AdSense or another advertising provider is enabled, providers may use cookies or similar technologies for ad delivery, measurement and personalization as permitted by applicable law and your choices. Appropriate consent controls will be implemented where required.

Contact

Use the Contact page to reach the site owner once the public support method is configured.