Date Difference Calculator

Count the days, weeks and months between two dates.

No login
No signup
No paywall
Nothing leaves your browser

Start date

End date

Include both the start and end date

Days between

Weeks: 4w 2d
Months and days: 1m 0d
Working days: 22

Results update as you type.

How the difference is counted

The plain day count is the number of midnights crossed between the two dates. That is the figure most agreements mean when they refer to a number of days, and it is why a stay from the 1st to the 4th is three nights rather than four days.

days = (end - start) / 86400000

inclusive days = days + 1

working days = count of days where weekday is Mon to Fri

Both dates are converted to UTC midnight before subtracting. Without that step a daylight-saving change falling between the two dates makes one day 23 or 25 hours long, and the result silently comes out one day short.

Frequently asked questions

Does the count include both the start and end date?

By default it does not — the result is the number of nights between the two dates, which is what most contracts, notice periods and hire agreements mean. Tick the inclusive option to count both endpoints, which is the convention for things like conference days.

How are working days counted?

Working days exclude Saturdays and Sundays. Public holidays are not deducted, because they differ by country and by state, so treat the figure as a five-day-week count rather than a payroll-accurate one.

Why is the number of months not simply days divided by 30?

Because calendar months vary between 28 and 31 days. The month figure here counts completed calendar months from the start date, then reports the leftover days separately, which is how notice periods and rental terms are normally read.

Can I count to a date in the past?

Yes. If the end date is earlier than the start date the tool reports the gap without a negative sign and notes the direction, so you can use it to count elapsed time as well as time remaining.

Is anything I enter sent to a server?

No. The calculation runs entirely in your browser. No dates are uploaded, stored or logged.