How it works
Date math is trickier than it looks — months have different lengths and leap years add a day every four years. This calculator handles all of it, including a business-days (weekdays only) count.
Frequently asked questions
How are leap years counted?
Years divisible by 4 are leap years — except centuries, unless divisible by 400. So 2000 was leap, 1900 wasn't.
What counts as a business day?
Monday–Friday, excluding public holidays. This calculator counts weekdays; holidays vary by country.
Why 30.44 days/month?
365.25 ÷ 12 — the average month length including leap years.
Disclaimer: This calculator provides estimates for educational purposes only and is not financial, tax, or legal advice. Consult a qualified professional before making financial decisions.