How to Use the Date Difference Calculator
- Enter the start date.
- Enter the end date.
- Choose whether to include the end day in the count.
- Read the difference in days, weeks, months and years.
Frequently Asked Questions
Does it account for leap years?
Yes. The calculation uses real calendar dates, so leap years and varying month lengths are handled correctly.
What does 'include end date' do?
Including the end date counts both the first and last day (inclusive), adding one to the total — helpful when counting event days or notice periods.
Can I calculate a difference across many years?
Yes. Any two valid dates work, whether they're days or decades apart.