What next?
A gap between two dates gets read as days, working days or years.
How to use this calculator
- Enter the start date.
- Enter the end date.
- Read the total difference in days, weeks, months and years.
What your result means
The total counts the calendar time between the two dates. Whether the end day itself is included depends on the measure shown, so check both dates when a single day matters for a deadline.
Why this one is different
One gap is reported two ways at once: broken up the way a calendar reads it, in years, months and days, and flat as a running count of days and of weeks. The flat count is the row to quote in a contract or a claim; the breakdown is the one to say out loud. Each is labelled with which it is, so neither gets copied in place of the other.
Why "how many days until..." is harder than it looks
Months have 28 to 31 days, leap years add a wildcard, and counting inclusively or exclusively changes the answer. Get it wrong and deadlines, notice periods and holidays land on the wrong day.
Whether you’re counting down to a wedding or working out a contract notice period, letting the calendar do the borrowing removes the guesswork — and the off-by-one errors.
How it works
The calculator counts the exact number of whole days between your two dates using the real calendar, then converts that into weeks and a calendar-accurate years/months/days breakdown. Leap years are handled automatically.
Worked example
Days between 1 March 2026 and 25 December 2026:
April to November = 244 days
December 1–25 = 25 days
Total = 299 days (42 weeks and 5 days)
The calculator counts elapsed days, so the start date itself is not included. Add one if you need an inclusive count — the classic off-by-one in deadline maths.
Inclusive or exclusive: the question that changes the answer by one
Ask two people how many days there are from 1 March to 8 March and you will get 7 and 8. Both are defensible. Seven is the elapsed count — the number of nights, the number of days of interest on a loan, the answer arithmetic gives. Eight is the inclusive count, which is what you want when booking a hotel, counting notice periods or working out how many days of a festival you can attend.
This tool reports the elapsed count, which is the standard convention for date arithmetic and the one every spreadsheet uses. If you need the inclusive figure, add one. What matters far more than the tool's default is knowing which convention the thing you are counting for uses: contractual notice periods, court deadlines and visa durations each have their own rule, and they are not all the same.
The other reason a difference can surprise you is calendar months. From 31 January to 28 February is one calendar month, but 28 days; from 1 June to 1 July is also one month, but 30. There is no contradiction — months are simply not a fixed unit. The tool gives you both readings, whole months plus leftover days as well as a plain day count, so you can quote whichever the situation actually calls for.
Frequently asked questions
Is the end date included?＋
The count is the number of days between the two dates, i.e. exclusive of the start day. Add one if you need to count both endpoints.
Can the dates be in any order?＋
Yes — the result is always the absolute difference, so order doesn't matter.
Why does the month count sometimes look wrong?＋
Months have different lengths, so 31 January to 28 February is one month by calendar reckoning but 28 days. The tool reports whole calendar months first and then the leftover days.
How do I count only working days?＋
Use the working days calculator, which excludes weekends and any holidays you enter. This tool counts every calendar day.
Are leap days included?＋
Yes. Every 29 February falling inside the range is counted, which is why some year-long spans come to 366 days.
Does it handle dates before 1900?＋
Yes, using the proleptic Gregorian calendar. Historical dates before the Gregorian changeover, which varied by country, may not match contemporary records.
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Assumptions & limitations
Date arithmetic has more edge cases than it appears to:
- Counts elapsed calendar days: the end date is included, the start date is not. Inclusive counting gives one more.
- Uses the proleptic Gregorian calendar, including the rule that century years are leap years only when divisible by 400 — so 2000 was, and 1900 was not.
- Ignores time of day and time zones. Two dates a day apart across a daylight-saving change are still one day apart here.
- For contracts and deadlines, check whether "days" means calendar days or business days — the working days calculator handles the second case.