Date Difference Calculator — Days Between Two Dates
About the Date Difference Calculator
This calculator measures the exact span between two calendar dates. It returns the difference in total days and total weeks, plus a calendar-accurate breakdown in years, months and days — the format contracts, HR systems and visa forms usually ask for.
Common uses include counting down to deadlines, measuring project durations, verifying notice periods in contracts, and tracking milestones. Leap years are handled by the real calendar, not by a fixed 365-day approximation.
How to use the Date Difference Calculator
- Set the start date.
- Set the end date — the order does not matter; the span is the same either way.
- Read the results: total days and weeks, plus the years/months/days breakdown.
Frequently asked questions
Is the end date included in the count?
The calculator reports the difference between the dates (end − start), the convention spreadsheets use. If you need an inclusive count of days in a period, add 1 to the total days.
How is the months-and-days breakdown computed?
By walking the calendar from the start date: full years, then full calendar months, then remaining days — the same method as age calculation.
Can it count into the past?
Yes. Swap the two dates or enter them in any order; the difference is reported as a positive span.
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