1
Pick two dates or use Add/subtract
Use Between two dates for a span, or Add/subtract to move forward or backward from one date.
Date difference
Compare two dates or add and subtract years, months, weeks, and days from one date.
Off = all calendar days. On = business days (excludes Sat–Sun).
Select a start and end date to see the difference.
Pro Tip
Weekdays-only counts use Monday–Friday business days (Saturday and Sunday excluded). Calendar breakdown (years, months, weeks, days) always follows full calendar math between your two dates.
How to Use the Date Difference Calculator
2
Choose day count type
Toggle weekdays only to see business-day totals, or leave it off for all calendar days.
3
Read the dashboard
See total days, then years, months, weeks, and days in separate cards. Add/subtract mode shows the resulting calendar date.
Date Calculation Complexities
Calendar span uses full dates (no time-of-day), so results match day-level differences. Leap years and month lengths are handled by the calendar library.
Business-day counts follow the Monday–Friday convention in date-fns (weekends excluded). This is useful for SLA and work schedules; it is not the same as public holidays.
Frequently Asked Questions
Total days counts every calendar day between the two dates. Weekdays only counts Monday through Friday, excluding Saturday and Sunday.
We apply years, then months, then weeks, then days in order on your start date, using calendar arithmetic (same as date-fns add/subtract).
Leap day (Feb 29) is part of the calendar. Spans and additions respect real month lengths automatically.