About the Day Counter

Counting days between dates is the basis of deadlines, billing cycles, and countdowns. By default the count is exclusive of the end date — 90 days from January 1 lands on April 1, not March 31 — which is why the calculator offers an 'include end day' toggle.

Business Planning

For scheduling, split the span into weekdays and weekend days: project tasks land on weekdays, and a 10-day calendar span typically contains 8 weekdays and 2 weekend days. Holidays are not excluded here, so adjust for local public holidays separately.