In short: A date difference calculator counts the days, weeks, months and years between two calendar dates, and can count business days (Monday to Friday) only.
About Date Difference Calculator
How many days until a deadline, a holiday or a due date? How long has a contract been running? Counting across months of different lengths and leap years by hand is error-prone, and spreadsheets need the right formula.
This calculator gives the exact difference in total days, in weeks and days, and in years, months and days the way people say it (“2 years, 3 months and 5 days”). It also counts business days — Monday to Friday — which is what most notice periods and delivery estimates use. Public holidays differ by country and are not subtracted.
How to use Date Difference Calculator
- Pick the start date and the end date.
- Tick Include the end date if both the first and last day should count (as with hotel nights versus days of a trip).
- Read the total days and the breakdown.
- Use the business-day figure for working-day deadlines.
Examples
From 5 November to 31 December is 56 days (8 weeks).
From Monday 2 March 2026 to Friday 27 March 2026, inclusive, is 26 days but only 20 business days.
Frequently asked questions
Does it account for leap years?
Yes. Calculations use real calendar dates, so 29 February is counted when it exists.
Are public holidays excluded from business days?
No. Holidays vary by country and region, so subtract them yourself if needed.
Why might my answer differ by one day?
Whether to include the end date is the usual cause. Tick or untick the option to match your convention.
Do time zones matter?
No. The calculator works with whole calendar dates.
Updated November 2026 · Free, no signup · How we build and test tools