Days Between Dates Calculator
Pick a start and end date to count the days between them — with the total also shown in weeks, in months and days, and as working days (Monday–Friday). An include-end-date toggle lets you switch between the two common counting conventions instantly.
How it works
The calculator counts calendar days from the start date to the end date. By default the end date is not counted (2 → 5 January is 3 days); tick “include end date” to count it as well, which is how notice periods and challenges are often measured.
Weeks are the day count divided by 7; the months figure counts whole calendar months first, then the days left over — so 15 March to 20 May shows as 2 months 5 days.
Worked example: 1 June to 29 August. June contributes 30 days (1 June to 1 July), July 31 and August 28, so the gap is 89 days — 12 weeks and 5 days, or 2 months and 28 days. Tick “include end date” and the total becomes 90. Running both versions takes a second and settles most disagreements about a date range.
Calendar arithmetic is handled exactly: the calculator counts real dates, so leap years take care of themselves — a range crossing 29 February in a leap year is simply one day longer than the same range in an ordinary year. No average month lengths or 30-day approximations are used anywhere in the day count.
The classic error is the off-by-one (fencepost) mistake: “from the 2nd to the 5th” is 3 days if you count the gaps but 4 if you count both endpoints — and neither is wrong, they answer different questions. Decide first whether your context counts both ends (inclusive periods, medication courses) or only the elapsed gap (countdowns), then set the toggle to match rather than adjusting the answer by hand.
Working days exclude Saturdays and Sundays but NOT bank holidays, which vary by nation and year (England & Wales, Scotland and Northern Ireland have different sets). For deadlines that skip bank holidays, subtract them manually from the working-day figure. Times of day are ignored throughout — the tool works in whole calendar days.
FAQ
Should I include the end date in the count?
It depends what you are measuring. For “how many days until” questions (countdowns, days to a holiday) you normally exclude the end date. For durations where both ends count — hotel nights vs days, medication courses, or inclusive contract periods — include it. The calculator has a toggle so you can see both figures instantly.
How are working days calculated?
The tool walks through every date in the range and counts only Mondays to Fridays, giving the standard business-day count. Bank holidays are not deducted because they differ between England & Wales, Scotland and Northern Ireland and change year to year — check the gov.uk bank holiday list for your nation and subtract any that fall inside your range.
Why do two date calculators give different month answers?
Because months have different lengths, there is no single correct way to express a gap “in months”. This tool counts complete calendar months from the start date, then the remaining days: 31 January to 1 March is 1 month 1 day. Others divide the day count by an average month length (30.44 days), which can differ by a day or two either way.
Does the calculator handle leap years correctly?
Yes — it counts actual calendar dates, so 29 February is included whenever the range crosses it in a leap year. A range spanning February in a leap year is one day longer than the same dates in an ordinary year, and the weeks and months breakdowns reflect the true count rather than any averaged month length.
How many working days are there in a year?
A 365-day year is 52 full weeks plus one extra day, so it contains 260 weekdays if that extra day falls at the weekend and 261 if it falls on a weekday; a leap year's two extra days can push the total to 262. Bank holidays are not deducted from these figures — subtract your nation's set for a true business-day count, as England & Wales, Scotland and Northern Ireland each have different ones.
Can I count the days from today to a future date?
Yes — set the start date to today and the end date to your target, leaving “include end date” off for a conventional countdown. The result then reads as days remaining: today to tomorrow shows 1 day, and the target day itself is not counted, matching how most people say “3 days to go”. Flip the toggle if your context counts the final day too.