Date Difference Calculator
Count days, weeks and business days between two dates.
How to use the Date Difference Calculator
Pick a start and end date to see the exact number of days, weeks + days, weekdays and approximate months and years.
Formula
Days = (End − Start) ÷ 86,400,000 ms
Worked example
1 January to 31 December is 364 days (365 including the end date).
Frequently asked questions
Are holidays excluded from business days?
Only weekends are excluded; subtract public holidays in your region manually.
Results are estimates for educational and planning purposes. Always confirm important financial, health or legal decisions with a qualified professional. Last reviewed 2026-09-27.