Question 1

Does this calculator include or exclude the start and end dates?

Accepted Answer

The count is exclusive of the start date and inclusive of the end date — the standard convention for duration calculations. For example, from Jan 1 to Jan 3 is 2 days (Jan 2 and Jan 3). If you need to include the start date, simply add 1 to the total days result.

Question 2

How are business days calculated?

Accepted Answer

Business days count Monday through Friday only, excluding Saturdays and Sundays. We do not subtract public holidays, since holidays vary by country, state, and employer. For precise deadline calculations that require holiday exclusions, manually subtract the known holidays from your result.

Question 3

What happens if I enter the end date before the start date?

Accepted Answer

The calculator automatically handles reversed dates — it always computes the positive difference between the two dates regardless of the order you enter them. You'll see the same result either way.

Question 4

How does the calculator handle leap years?

Accepted Answer

JavaScript's Date object handles leap years natively. February 29th is counted as a normal day when it exists in the range. A 4-year span that includes a leap year will have 1,461 days instead of 1,460.