How to use the Date Difference Calculator

Select a start date and an end date.
Optionally check Exclude weekends to count only working days (Monday-Friday).
Click Calculate to see the difference in days, weeks, months, and years.

What each result means

Days: the exact number of calendar days between the two dates (inclusive or exclusive of the end date depends on the convention; this tool calculates the difference, so day 1 to day 2 = 1 day)
Weeks: total days divided by 7, rounded down
Months: approximate count of full calendar months
Years: approximate count of full calendar years
Working days: total days minus Saturdays and Sundays (public holidays are not excluded: add those manually if needed)

Common use cases

Project planning: count working days between project start and deadline
Contract periods: calculate the length of a rental, employment, or service contract
Age calculation: find someone's exact age in days, months, and years
Event countdown: find how many days until a future date
Invoice due dates: calculate when a payment is due (e.g. net 30 days)
Warranty and guarantee periods: check whether a claim is within the covered period

Note on months and years

Months and years in the results are approximate because calendar months have different lengths (28-31 days). The day and working-day counts are always exact.