Nothing you calculate leaves your browser
Every calculator on SunMoonCalc runs entirely on your own device. The location, date and time you enter are processed locally and are not transmitted to us, logged by us or stored on a server. There is no account, no sign-up and no personal profile attached to a calculation.
That is why the site works with JavaScript disabled for the text and the formulas, and why you can use it on a shared or public computer without leaving a trace behind.
Advertising and cookies
This site is supported by third-party advertising, including Google AdSense. Third-party vendors, including Google, use cookies and similar technologies to serve ads based on your prior visits to this and other websites. That is how the advertising works, and it is also why you may see ads that are not about astronomy.
You can opt out of personalised advertising through the Google Ads Settings, and you can opt out of third-party vendor cookies more broadly through aboutads.info. Blocking cookies does not break any calculator here.
No analytics trackers
There is no Google Analytics, no tag manager and no first-party analytics script on this site. We do not build a profile of you across pages or sites. The only data that leaves your browser because of an advertisement is whatever the advertising network decides to send, which is outside our control and is covered by the network's own policy.
Feedback you choose to send
If you use the feedback form at the bottom of a page, we receive what you typed and, only if you choose to type it, your email address. We use it to reply and to fix what you reported. We do not add feedback senders to a mailing list and we do not sell or share the address.
Server logs
Like most websites, our hosting provider may keep standard technical information in server logs — IP address, browser type, requested page, timestamp — for security, abuse prevention and keeping the site running. Those logs are not used to identify you and are not combined with anything you send us.
Your choices
- You can block or delete cookies in your browser. Every calculator still works, because none of them depends on a cookie.
- You can leave the feedback form blank of an email address if you would rather not give one.
- You can ask us to delete a feedback message you sent. Use the form on the contact page and say so.
Contact
Questions about this policy, or a request to remove something you sent, can go through the form on the contact page. The about page explains what the site is and who runs it, and the editorial policy explains how the figures are produced.
Effective: 28 October 2026.