Date Difference Calculator

Calculate how much time passed between two dates — in days, weeks, months and years, including or excluding the end date.

All calculations happen in your browser.

How to use Date Difference Calculator

  1. Pick the start and end dates.
  2. The difference updates instantly in days, weeks, months and years.
  3. Toggle “Include end date” if you want to count both days.

About this tool

Useful for project planning, deadlines, event countdowns and age checks. The tool handles leap years and varying month lengths correctly.

Frequently asked questions

How is the difference in months and years calculated?
Whole months and years are counted first (accounting for month lengths), then the remaining days are shown separately.

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