Date Difference Calculator
Days, weeks and weekdays between two dates.
Use the Date Difference Calculator tool
What this date difference calculator does
Date Difference Calculator measures the interval between two calendar dates. It reports total days, whole weeks and remainder days, the year-month-day span, and the number of Monday-to-Friday weekdays.
Calendar arithmetic is not simple subtraction. Months have different lengths and leap years add a day, so the year-month-day figure borrows from the previous month the way you would calculate it by hand. The total-day count remains the unambiguous number.
Why use it
- Count the days until a deadline or event.
- Work out a notice period or contract term.
- Estimate working days for a project plan.
How to use it
- 1Choose a start date and an end date.
- 2Read the total days, calendar span and weekday count.
- 3Use the swap button to reverse the direction.
Worked examples
Across a year
Input
1 January 2026 → 10 November 2026
Output
313 days · 10 months 9 days · 44 weeks 5 days
Leap year
Input
1 February 2024 → 1 March 2024
Output
29 days, because 2024 is a leap year
Common mistakes
- Counting the start date twice; the difference counts whole days between dates.
- Using business days as if public holidays were excluded; this count removes weekends only.
- Assuming every month is 30 days when converting a day count to months.
Frequently asked questions
Are both dates included?
Does it account for leap years?
Are public holidays excluded from weekdays?
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