Days Between Dates Calculator
Calculate the exact duration between two dates with calendar days, inclusive count, weekdays, weekends, weeks, months, years, countdown status, and add/subtract date tools.
How to calculate days between dates
The standard method is to subtract the start date from the end date. This gives the number of full calendar days between the two dates. For example, January 1 to January 3 is 2 days because two full days pass.
Include end date: Exclusive days + 1
Business days: Count only Monday through Friday
Tip: Date calculators often differ by 1 day because some include the end date and some do not. This tool shows both exclusive and inclusive counts so you can avoid confusion.
Inclusive vs exclusive day count
Exclusive counting treats the start date as day zero. This is common for elapsed time. Inclusive counting counts both the start and end dates. This is common for hotel stays, event periods, schedules, and legal or notice windows when both dates matter.
Business days and weekends
Business days usually mean Monday through Friday, excluding Saturday and Sunday. This calculator counts weekdays and weekend days separately. It does not remove public holidays automatically because holidays depend on country, state, and company policy.
Common uses
- Deadlines: Check how many days remain before a due date.
- Travel: Count trip duration and nights between dates.
- Work: Estimate weekdays and weekend days in a project window.
- Planning: Add or subtract 30, 60, 90, or custom days from a start date.
Example
From March 1 to March 10, the exclusive difference is 9 days. If you include the end date, the count becomes 10 days. If you also include the start date as day 1, be careful not to double count in contexts where only one endpoint should be included.