What DateTimeHQ does
DateTimeHQ is a collection of single-purpose date calculators: an age calculator, a date difference calculator, countdown and days-since tools, a business days counter, and a few others. Each one is built around a single question, such as how old, how many days, or what weekday, and answers it the moment you type a date in, with no submit-and-wait round trip to a server.
Every calculation happens in your browser using plain JavaScript date arithmetic. Nothing you type is uploaded anywhere, there's no account to create, and there's no ad-tech tracking pixel following you from page to page.
Why we built it this way
Most date calculators online are older tools that have accumulated years of ads, auto-playing widgets, and unrelated content around a small calculator buried in the middle of the page. We wanted the opposite: a page that loads fast, works the first time, and gets out of your way once you have your answer. That's also why the site ships without custom web fonts or images, just the system font your device already has, so pages stay light and quick even on a slow connection.
We also try to show our work. Every calculator page explains, in plain language, exactly how the result is worked out: how months of different lengths are handled, how leap years are counted, and why time zones don't change a date-only calculation, with a worked example you can check by hand. If a number doesn't match what you expected, you should be able to find out why from the page itself, not have to take it on faith.
Accuracy
All date arithmetic on this site runs on whole calendar days in UTC, which avoids a common class of bug where daylight saving changes silently add or remove a day near a clock change. Every calculator's underlying logic is cross-checked against independent date libraries before it ships. If you ever spot a result that looks wrong, we'd genuinely like to know. See the contact page for how to reach us.
How the site is funded
DateTimeHQ is free to use and doesn't require sign-up. Running the site costs very little since there's no server-side processing, but where it does cost something, we may show a small amount of unobtrusive advertising to cover it. See the privacy policy for details on what that involves and what, if anything, is collected while you use the calculators.