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.

How are weeks, months and years shown?

Weeks are whole weeks plus leftover days, so 59 days reads 8w 3d. Months and years are approximations (days divided by 30.4375 and by 365.25), because calendar months differ in length.

Days between dates

Pick a start date and an end date to find out exactly how many days are between them, with the gap also shown in weeks and approximate months and years. The result updates instantly as you change either date.

Start dateEnd date

End date is same day

0 days

Weeks

0w 0d

Approx months

0.0

Approx years

0.00

Today:

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 counts complete calendar months, shown as years and months, then the days since the last monthly anniversary. The page does not call any external library or server during the calculation. Dates are read at local noon in your browser's time zone, so a daylight saving change from the IANA rules built into the browser never moves a count to the wrong day.

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.
How are weeks, months and years shown?: Weeks are whole weeks plus leftover days, so 59 days reads 8w 3d. Months and years are approximations (days divided by 30.4375 and by 365.25), because calendar months differ in length.

Last reviewed September 30, 2026

Other pages for this tool

Related tools

Background reading: Complete guide to time tools