Free Date Calculator
Calculate days between two dates, or add/subtract days from a date. 100% in your browser.
How It Works
Enter two dates to calculate the difference in days, weeks, and months, or pick a base date and add or subtract a number of days. The tool displays the resulting date and the day of the week, formatted according to your locale. Leap years and month-length variations are handled automatically.
When to Use It
- Planning project deadlines — find out exactly how many business days until a delivery date.
- Calculating contract durations — determine the exact length between start and end dates for legal documents.
- Scheduling follow-ups — add 30 or 90 days to today to set reminders for client check-ins or warranty expirations.
Frequently Asked Questions
Does it account for leap years?
Yes. The calculator uses the browser built-in Date engine which correctly handles February 29 and all month-length variations.
Can I calculate negative days?
Yes. Enter a negative number in the days field to subtract days from your base date. The result will show the earlier date.
Is my data stored anywhere?
No. All calculations run entirely in your browser. No dates or results are sent to any server.
All calculations happen in your browser. No data is sent to any server.