In short
- Calculations run in your browser. Your inputs are not sent or stored.
- Google Analytics counts visits so I can see which pages help. Your inputs are removed first.
- No ads and no accounts.
- Like any website, each visit sends standard technical data, used only to deliver pages.
- If you email me, your message is used only to reply, and you can ask me to delete it.
- Nothing is sold or shared, so there is nothing to opt out of.
What you type into a calculator
Every calculation runs in your browser. The dates, times and numbers you enter are not sent to a server and are not stored.
Some calculators put your inputs in the page address so you can bookmark or share a result. Anyone you send that link to can see the values in it, and like any web address, the values travel with the link when someone opens it.
Technical data
Like every website, the servers that deliver these pages receive standard technical data with each visit, such as your IP address, browser type and the page you asked for. It is used only to deliver the pages and protect the site from attacks.
Analytics and cookies
The site uses Google Analytics to count visits and see which pages people find useful. It records things like the pages you view, how you arrived, your device and browser type, and your approximate location, such as your country or city. Google Analytics does not store IP addresses.
Before anything is sent, the calculator inputs are removed from the page address, so Google never receives the dates, times or numbers you enter. Analytics data is not used for advertising, and the advertising features of Google Analytics are switched off.
Google Analytics sets two first-party cookies, named _ga and _ga_ followed by an ID, which tell repeat visits apart. They last up to two years. Visitors in the European Economic Area, the United Kingdom and Switzerland get no analytics cookies: their visits are counted without them.
You can block these cookies in your browser settings or install Google's opt-out add-on. The site works the same either way. To learn how Google handles this data, see how Google uses information from sites that use its services.
There are no ads on the site. If that changes, this page will be updated first.
If you email me, I receive your email address and your message. I use them only to reply. Like any email, the message passes through the email service that delivers and stores my mail, which handles it only for that purpose. I don't add anyone to a mailing list or pass messages on to anyone else.
How long data is kept
Emails are kept for as long as a conversation is useful, and for no more than two years after the last message, unless you ask me to delete them sooner. Analytics data is kept for no more than 14 months and then deleted automatically. Standard technical data from visits is kept only for the short time needed to deliver pages and protect the site.
Selling or sharing data
I don't sell or share personal information, and I don't use it for targeted advertising. Google processes analytics data for me as a service provider and may not use it to advertise to you. Because nothing is sold or shared, there is nothing to opt out of, and browser privacy signals such as Global Privacy Control are respected by default.
Children
The site is not aimed at children under 13 and does not knowingly collect personal information from them.
Your rights, wherever you live
The site is used in the United States and around the world. Depending on where you live, including US states such as California and countries in the European Union or the United Kingdom, you may have the right to know what personal information I hold about you, to correct it, to have it deleted, and to object to how it is used. I give these rights to everyone, wherever they live. The personal information involved is an email you sent, which I use to reply because you asked me something, and analytics data, which is tied to a random cookie ID rather than your name and which I use to improve the site.
If you are unhappy with how I handled a request, you can also contact the data protection authority where you live.
Making a request
To ask what I hold about you or to have it deleted, write to [email protected]. You can also use the contact page. I reply within 30 days at the latest, and usually within 24 hours. There is no charge.
Changes
When this policy changes, the date at the top of the page changes with it.