Datumsrechner
Find the difference between dates or add/subtract days.
How is the date difference calculated?
The difference is calculated using exact calendar days between the two dates. The result also shows the equivalent in weeks, months, and years for convenience. Leap years are automatically accounted for.
Does this account for leap years?
Yes. All calculations use JavaScript's native Date object which correctly handles leap years, month lengths, and daylight saving time transitions.
How It Works
- Choose a calculation mode: Calculate the difference between two dates, or add/subtract a duration from a start date.
- Enter your dates: Use the date pickers or type dates in YYYY-MM-DD format. Time can be included for precision down to the second.
- Get the result: See the difference in years, months, weeks, days, hours, minutes, and seconds — all at once.
Why Use Date Calculator?
Counting days between dates manually is slow and error-prone — especially across month boundaries, leap years, and daylight saving time transitions. This calculator handles all the calendar edge cases correctly. Common uses include calculating contract durations, age verification, project timelines, days remaining until a deadline, how long since a specific event, payment due dates, and subscription renewal periods. The add/subtract mode is useful for calculating future dates by adding a number of business days, weeks, or months to a start date.
What You Can Calculate
- Date difference — exact days, weeks, months, and years between any two dates
- Add duration — find the date N days/weeks/months from a start date
- Subtract duration — find the date N periods before a reference date
- Age calculation — complete years, months, and days since a birthdate
- Business days — count only working days, excluding weekends