Date Difference Calculator
Find the number of days, weeks, approximate months, and approximate years between two dates for planning, deadlines, travel, billing periods, and schedules.
Formula
Days = absolute difference between dates Weeks = days / 7 Approximate months = days / 30.436875 Approximate years = days / 365.2425
Examples
Use date differences to count a project window, the length of a trip, the time until a deadline, or the number of days between two events.
Planning notes
- This calculator counts calendar date difference, not business days.
- Months and years are approximate because calendar months and leap years vary.
- For billing or legal deadlines, confirm the exact counting rule used by the relevant organization.
FAQ
Does this include the end date?
This version calculates elapsed difference between dates. Some countdown or billing rules include both start and end dates, which can add one day.
Can I enter dates in reverse order?
Yes. The calculator uses the absolute difference, so either order returns the same elapsed amount.
Does it count business days?
No. Weekends and holidays are not excluded in this version.