Date Difference Calculator

Pick two dates and instantly see the days, weeks, months and years between them.

Start date End date Include the end date (count it as a full day, +1)

Count the time between any two dates

This Date Difference Calculator tells you exactly how much time separates two calendar dates. Enter a start date and an end date and you instantly get the gap expressed several ways at once: a plain total of days, the same span in weeks, months and years, and a calendar-accurate breakdown like "2 years, 3 months and 12 days." It is handy for counting down to a wedding or trip, working out someone's age, measuring a project timeline, tracking a notice period, or settling how long ago something happened.

Whole days vs. including the end date

By default the tool counts the number of nights between the two dates, so July 1 to July 4 is 3 days. That is the right answer when you care about the interval itself. If you want to count both endpoints as full days — for example when totalling billed days, hotel nights charged, or days of leave — tick Include the end date and every result gains one day, making July 1 to July 4 read as 4 days. The order of your two dates does not matter: if the end date is earlier than the start date, the calculator swaps them automatically and still returns a positive answer.

How to use it

Click the Start date field and pick your first date.
Click the End date field and pick your second date.
Tick Include the end date if you want that final day counted (+1).
Press Calculate to see the days, weeks, months and years.
Use Use today for both to quickly reset to the current date.

Everything runs in your browser — no dates are ever uploaded.

FAQ

How are months and years counted?: The "years, months and days" breakdown is calendar-accurate: it walks real month lengths, so it respects that months vary from 28 to 31 days. The single-unit month and year totals use averages (30.44 days per month, 365.25 per year), so they can differ slightly.
Does it handle leap years?: Yes. The day count is based on actual calendar dates, so February 29 and leap years are included automatically.
Why do I get a decimal number of weeks or months?: Because most spans do not divide evenly. The decimal figures show the exact fraction, while the "X weeks and Y days" line gives the whole-number version.
Is my data private?: Completely. All calculations happen locally in your browser and nothing is sent to a server.