Days between dates
Pick a start date and an end date to find out exactly how many days, weeks, months, and years are between them. The result updates instantly as you change either date.
How it works
All date arithmetic uses the browser's native Date object. Day differences are computed by subtracting timestamps and dividing by 86,400,000 ms. Age is broken into complete years, remaining months, and remaining days by comparing each component of the date individually. The page does not call any external library or server during the calculation.
Processing runs in your browser
All calculations happen instantly in your browser tab. Our servers are not involved at any point.
Related operations
For working out an exact age in years, months, and days, try the age calculator. To convert any timestamp into a date, use Unix timestamp. For scheduling work across time zones, see the timezone converter.
Frequently asked questions
- How do I calculate days between two dates?
- Subtract the earlier date from the later date to get the difference in milliseconds, then divide by 86,400,000 (ms per day). This tool does that automatically.
- Does it include both the start and end date?
- The calculator counts the number of full days between the two dates, the end date minus the start date. To include both endpoints, add 1 to the result.
- Can I calculate past or future dates?
- Yes. Any date combination works. You can calculate the difference between historical dates or dates far in the future.