Dates
Days Between Dates
Calculate the exact number of days, weeks, or months between two dates.
Days Between Dates
Enter an end date above to see the result
"How many days between these two dates" sounds simple until you hit the inclusive/exclusive question — do you count the start date itself, or only the nights/days that separate them — which is exactly where many quick mental calculations and even some calculators quietly disagree with each other.
Project planning, travel itineraries, and legal notice periods are all common real uses for this tool, and in every one of those contexts, getting the inclusive/exclusive convention right is exactly the difference between correctly meeting a deadline and being a day off in either direction.
How the Days Between Dates works
Each date is converted to an ordinal day count using the Gregorian calendar (correctly counting every real leap day inside the span), then subtracted. By default this tool counts exclusive-of-the-start-date, matching the everyday meaning of "how many days have passed," with an inclusive option available for cases like counting the total nights of a stay.
This tool is the most frequently reused calculation on the entire site under the hood — the Age Calculator, Days Since Calculator, and several countdown tools all ultimately reduce to some form of "days between two dates" internally, just framed differently for their specific use case.
Worked example
From January 1, 2026 to July 12, 2026: January (31) + February (28) + March (31) + April (30) + May (31) + June (30) = 181 days, plus 12 more days into July = 193 days total — or, expressed as weeks, 27 weeks and 4 days.
Edge cases this tool handles correctly
- Inclusive vs. exclusive counting
- A 3-night hotel stay and a 4-day span are both "correct" descriptions of the same two dates depending on which convention you use — this is a common source of off-by-one disagreements, so the tool states which convention it's using and offers the other as a toggle.
- Date order
- You can enter the two dates in either order — the tool takes the absolute difference and notes which date is earlier.
- Spans crossing leap years
- Leap years inside the range are automatically counted correctly because the underlying conversion is genuine calendar arithmetic, not an approximation based on an average year length.
- Same date entered twice
- Entering the identical date for both fields correctly returns zero days, weeks, and months — a useful sanity check that confirms the tool isn't silently assuming a minimum span.
- Time zones aren't part of this calculation
- This tool works on calendar dates only, with no time-of-day or time zone component — two people in different time zones both entering the same two calendar dates get the identical answer, since a calendar date is the same day everywhere it's written down.
- Legal notice periods often specify the counting convention explicitly
- Contracts and statutes that reference a "10-day notice period" or similar sometimes state explicitly whether the day the notice was given counts toward that total — when a contract is silent on the point, this is exactly the inclusive/exclusive ambiguity above, and the tool's toggle lets you check the result under either reading rather than assuming one is universally correct.
- Business days vs. calendar days
- This tool's day count includes every calendar day, weekends included — a deadline or contract specifying "business days" instead needs the Business Days Calculator, which excludes weekends and, optionally, public holidays from the same underlying range.
Frequently asked questions
Is the start date counted or not?
By default the tool counts exclusive-of-the-start-date (matching "how many days have passed"), with an inclusive toggle for the alternative convention.
My contract says a 10-day notice period — does this tool tell me which counting convention applies?
No — that's a matter of the specific contract's or statute's own wording; the tool lets you check the day count under either the inclusive or exclusive convention so you can compare against what your document actually specifies.
Does this count exclude weekends automatically?
No — it counts every calendar day including weekends; for a working-day count that excludes weekends and holidays, use the Business Days Calculator instead.
Does date order matter?
No — enter either date first; the tool reports the absolute gap and notes which is earlier.
Can I get the answer in months or years instead of just days?
Yes — the tool also offers a calendar-unit breakdown similar to the Age Calculator's years/months/days format, alongside the raw day total.
Does it work across many centuries?
Yes — the conversion is genuine calendar math, not a table capped at some fixed span of years.
What happens if I enter the same date twice?
The result is exactly zero — no days, weeks, or months have elapsed between a date and itself.
Can I get the answer in weeks instead of just days or months?
Yes — the result can be expressed as a whole-weeks-plus-remainder figure in addition to the total day count and the months/years breakdown.