Date Calculator by Noel Chew answers a question that shows up constantly: how many days until a deadline, how far apart two events actually are, or what date lands 90 days from today. Instead of installing an app for a question you have once and forget about, we built Day Span, a free date calculator that runs right here in your browser. Pick your dates and the answer updates the moment you change anything.
Calculate dates now
It opens with a working example already filled in, so you see a real result before you touch anything. Switch modes to add or subtract days instead of comparing two dates.
How to use it
Day Span has two modes. “Between two dates” takes a start and end date and shows the total days, plus a friendly years/months/days breakdown, total weeks, and how many of those days are weekdays versus weekend days. “Add or subtract days” takes a start date and a number of days, which you can type directly, nudge with the plus and minus buttons, or drag on the slider, and shows the resulting date and its day of the week.
Both modes update live, so there is no calculate button to press. A small timeline bar under the result moves as you change dates, giving you a visual sense of the span. If you enter an end date before the start date, Day Span tells you clearly and still shows the correct span rather than an error. Your last dates and mode are saved on your device, so they are there next time you open the page. Nothing leaves your browser.
How it compares to Date Calculator
Day Span does one thing: turn two dates, or a date plus a day count, into an accurate answer, fast, on anything with a browser. The full Date Calculator app goes further. It can save multiple date calculations for later, set reminders tied to a specific date, and sync entries so you can check them from a calendar view instead of typing dates in each time.
We kept the core loop: pick your dates or your day count, and watch the result and the breakdown update instantly, with correct handling of leap years and months of different lengths. We deliberately left out saved calculations, reminders, and any kind of calendar sync, because a page you land on mid-search should answer the one question you came with in a few seconds, not ask you to set anything up first.
Our honest advice: use Day Span for a quick, one-off calculation, like checking how many days until a flight or what date a 30-day return window ends. Install the app if you regularly track multiple dates and want reminders or a saved history instead of retyping dates each time.
Get the full app
Date Calculator by Noel Chew is free on Android and adds saved calculations and reminders on top of the basic date math.
Frequently asked questions
How do I calculate the number of days between two dates?
Enter the start date and end date in the “Between two dates” mode above and the total day count appears instantly, along with a years/months/days breakdown. The calculation accounts for leap years and different month lengths automatically, so you never need to count on a calendar by hand.
Can I add or subtract days from a date?
Yes. Switch to “Add or subtract days,” set your starting date, and enter a number of days, positive to move forward or negative to move backward. The resulting date and its day of the week appear immediately, and you can fine-tune the count with the plus and minus buttons or the slider.
What happens if I enter an end date before the start date?
Day Span shows a clear note that the end date comes before the start date, then displays the correct span between the two dates instead of an error or a broken result.
Is this date calculator free and does it work offline?
Yes, completely free with no signup. Once the page has loaded, it keeps working without a connection, and your last used dates are saved in your browser’s local storage on your device only.
Is this the official Date Calculator app?
No. Day Span is an original tool we built, inspired by the quick-check problem Date Calculator solves. It is not affiliated with, endorsed by, or connected to Noel Chew. If you want saved calculations and reminders, get the official app above.
