Date Difference Calculator
Count the exact time between two dates — years, months, days, weeks, business days, and hours.
Fill in the fields above to see your result instantly.
This date difference calculator measures the duration between any two dates. It counts the exact calendar span as years, months, and days — borrowing the real length of each month and accounting for leap years — and also gives you the total in days, weeks, and hours. The business-days figure counts only Monday to Friday, which is handy for project timelines and notice periods. Enter the dates in any order; the calculator measures the gap between them.
How to use the Date Difference Calculator
- 1
Enter the start date
Pick the earlier date — or either one; order doesn't matter.
- 2
Enter the end date
Pick the other date you want to measure to.
- 3
Choose how to show it
Switch between years/months/days, weeks and days, total weeks, or total days. Results are instant.
Examples
Frequently asked questions
How do you calculate the number of days between two dates?
The calculator converts both dates to a day count and subtracts them, giving the exact number of whole days between the two — then derives weeks, months, and hours from that span.
What counts as a business day?
Business days are Monday through Friday. The business-days figure excludes Saturdays and Sundays but does not account for public holidays, which vary by country.
Does the calculator include both the start and end dates?
It measures the span between the two dates, so the total days is the difference between them. Add one if you need to count both the first and last day inclusively.
Can I enter the dates in either order?
Yes. The calculator always reports the absolute duration, whichever date you put first.