Date Difference Calculator
Days between two dates, with the same span given in weeks, in years and months, and in business days once your own holidays come out.
Date difference
Choose two dates to begin.
What the box did with each line
One date per line, YYYY-MM-DD — and every line comes back above with what the tool did with it.
How to use
- Choose a Start date. Until both date boxes are filled, the answer says Choose two dates to begin.
- Choose an End date. Which of the two comes first changes nothing on the page.
- Read the answer for the years, months and days phrasing of the span.
- Look at Total days, Weeks and Business days below it. Weeks is given as whole weeks plus the remainder, so 115 days shows as 16 weeks and 3 days.
- Type your public holidays into the holiday box, one YYYY-MM-DD per line. Only the business-day card moves, and a list above the cards says what each line did.
- Add a Start time and an End time to bring in hours and minutes. Both need a value before the second pair of cards appears.
About this tool
Pick two dates and the days between them turn up four ways at once. The answer phrases the span the way a person says it out loud, something like 3 months and 24 days, and leaves out any unit that comes to zero. Under it are the plain running total, the same stretch written as whole weeks plus whatever days are left over, and a working-day count. Nothing needs pressing. The cards fill the moment both boxes hold a real date.
Business days deserve their own paragraph. Saturdays and Sundays drop out by themselves. Nothing else does, because no country's holiday calendar is built in, and a weekends-only figure that is honest everywhere beats one that is quietly wrong outside its home country. 1 September to 25 December 2026 works out at 115 total days, 16 weeks and 3 days, and 83 business days. Paste 2026-11-26 and 2026-12-25 into the holiday box and the business figure falls to 81.
Fill both optional time fields and two extra cards appear. 2 March at 09:00 through 5 March at 17:30 reads 3 days, 8 hours and 30 minutes in one of them and 80 hours in the other. The arithmetic runs on the wall clock, which is why a daylight-saving switch inside the span never shifts an answer by a day, though on the night the clocks change the hours really worked are one more or one fewer than the card shows. Order is free too. Put the later date in Start and the same figures come back.
Kickoff to delivery, with the honest working-day number
A project signed on Monday 14 September 2026 delivers on Thursday 24 December. The answer phrases it 3 months and 10 days; below that sit 101 total days, 14 weeks and 3 days, and 73 business days with the weekends already gone.
Then the local calendar gets its say. Type 2026-10-20 and 2026-11-26 into the holiday box, one per line, both weekdays the office is shut, and only the business-day card moves, down to 71, with each line listed above it as applied. That is the number the plan should be built on, and the difference between 73 and 71 is a slipped deadline explained in advance.
Good to know
- Business days here mean Monday to Friday, full stop. A Sunday-to-Thursday week, a half-day Saturday, and your country's public holidays are all invisible until you type those dates in yourself, and a line that isn't a YYYY-MM-DD date changes nothing, its row in the list saying why.
- A holiday typed on a Saturday or Sunday changes nothing: weekends leave the business-day count before the holiday list is consulted, so only dates landing Monday to Friday move the number, and a reused list can never subtract the same day twice.
Frequently asked questions
Which days count as business days?
Every day in the span that lands on a weekday. Weekends come out automatically, as does any date sitting in the holiday box. The start date is excluded and the end date is included, so Monday to Friday counts four.
Does the end date count as one of the days?
It does. The count runs from the day after your start date up to and including the end date, so the total is end minus start and two identical dates give zero.
Why doesn't the years and months line match total days divided by 365?
Because months come in different lengths. The answer walks whole calendar months forward from your start date and then counts the days left over, which is how people state a duration out loud. Total days is the exact count. The years, months and days line is the readable version of the very same span.
Can I bring the time of day into it?
Add a start and an end time and two more cards appear, one with the span as days plus hours and minutes, one with the whole thing as a number of hours. Leave the time fields empty and you get whole dates only. For the gap between two clock times, the time difference tool suits better.
Missing something in Date Difference Calculator? Suggest a feature →
Tell someone who needs this.