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Free days between dates calculator. Find the number of days, weeks, and approximate months or years between two calendar dates.
Last updated 14 October 2026
Measured: 1 March to 2 March gives 1 day. The answer is the end date minus the start date, which counts the gaps between the days rather than the days themselves.
That is the right answer to “how many days until” and the wrong answer to “how many days am I on holiday”. If you need the inclusive count, the one that counts both end dates, add one. A booking from 1 March to 8 March is 7 days apart and 8 days of accommodation, and that off-by-one is the single most common mistake with any date calculator, including this one.
Both dates are converted to UTC midnight before being subtracted. That removes a whole class of bug that catches date calculators built on local time: in a week containing a clock change, one of the days is 23 or 25 hours long, so dividing the elapsed milliseconds by 24 hours gives a fraction, and rounding it can give an answer a day out.
Measured across the United States spring-forward weekend, 7 March to 9 March 2026, this tool gives 2 days, which is correct. You can rely on that wherever you are: the result does not depend on your time zone, and it will not change if you run it again from another country.
The one consequence to be aware of is that the dates are read as plain calendar dates, not as moments. So “today” means the calendar day you see on your own clock, which the tool fills in for you, and if you are near midnight in a zone far from UTC, your idea of today and the date in the box were agreed when the page loaded.
There is no 30-day month or 365-day year anywhere in the day count. Measured:
The Gregorian rule behind those numbers is that a year is a leap year if it divides by 4, except centuries, except centuries dividing by 400. So 2024 and 2000 are leap years and 1900 and 2100 are not. The day count here follows the calendar, so you do not have to think about it.
Only the day count is exact. The others are that number divided by a constant, and the page labels the last two “approx” for a reason worth spelling out:
So never quote the months or years figure as a calendar age or a contract term. One calendar year is one year whatever its length, and this will tell you 0.999 or 1.002. For a calendar-accurate breakdown in years, months and days, use Age Calculator, which walks the calendar instead of dividing.
An end date before the start date gives a negative answer, which is deliberate: the sign tells you the direction. Measured, 10 March to 1 March gives -9 days and says “from start to end (negative)”. Ticking Absolute gives 9 days apart.
Leave it unticked when you are counting down to something and want to know whether it has passed. Tick it when you only want the gap. Two identical dates give 0 either way.
Nothing is uploaded. The arithmetic runs in your browser and the dates never leave your device.
Date.UTC. developer.mozilla.orgdate input type. developer.mozilla.orgEvery behaviour and every figure on this page was measured against this tool as it is published, in a browser, on 14 October 2026. Where the page says what the tool does not do, that is a statement about this tool, not about date arithmetic in general.
Because the count is exclusive: it is the end date minus the start date, so it counts the gaps rather than the days. That is right for “how many days until” and wrong for “how many days of holiday”. Add one for the inclusive count.
No. Both dates are converted to UTC midnight before being subtracted, so there is no 23-hour or 25-hour day to divide by. Measured across the US spring-forward weekend, 7 to 9 March 2026 gives exactly 2 days, and the answer does not depend on where you are.
Yes, exactly, because it follows the calendar rather than approximating. Measured: February 2024 to March 2024 is 29 days, February 2026 to March 2026 is 28, a common year is 365 days and a leap year is 366.
Because the months figure is the day count divided by 30.4375, the average month length, not a calendar count. The years figure divides by 365.25 for the same reason, which is why a common year reads 0.999 and a leap year 1.002. Both are labelled approximate. For a calendar-accurate breakdown use Age Calculator.
No. It counts every calendar day, and there is no working-day option. Public holidays differ by country and region and would need a maintained list per jurisdiction, which this tool does not have.
Your end date is before your start date, and the sign is telling you so. That is useful when you are counting down to a deadline and want to know whether it has gone. Tick Absolute if you only want the size of the gap.
No, it only measures between two dates you supply. There is no date-plus-period mode.
No. The arithmetic happens in your browser and nothing leaves the page. Nothing is saved either, so refreshing resets the fields to today and a month ago.