Date Difference Calculator
Find the exact number of days, weeks, and months between any two dates — all in your browser, no signup needed.
How to calculate the difference between two dates
- Enter your start date and end date using the date pickers above.
- Click Calculate Difference.
- The result shows total days, weeks and remaining days, and approximate months and years.
- Use the swap button to reverse the two dates without retyping.
About the calculations
The total days count is exact and based on the Gregorian calendar. Weeks and remaining days are derived from that total. The months and years figures are approximate — they use 30.4375 days per month (365.25 ÷ 12) and 365.25 days per year, which accounts for leap years on average. For exact year/month/day breakdowns, use the Age Calculator.
Privacy — runs in your browser
All calculations happen locally using the JavaScript Date API. No data is uploaded to any server. No signup required.
Frequently Asked Questions
Does the start date count?
No — the tool counts the days between the two dates, not including the start date itself. If start and end are the same date, the result is 0 days. If you want to include both endpoints, add 1 to the result.
What if my end date is before my start date?
The calculator automatically uses the earlier date as the start and the later date as the end, so you always get a positive result.
Why are months and years "approximate"?
Calendar months vary from 28 to 31 days, so there is no single exact conversion from days to months. The tool uses the average month length (30.4375 days). The Age Calculator gives exact years, months, and days instead.
Can I calculate business days?
Yes — use the Business Days Calculator to count only weekdays between two dates.