Days between

Weeks
Approximate months
Working days (Mon–Fri)
Start date plus the offset

How it works

Counting days between dates by hand goes wrong at month and year boundaries, and leap years catch almost everyone. This counts the actual elapsed days, so February and the thirty-one-day months take care of themselves.

Working days exclude Saturdays and Sundays but not public holidays, which vary by country and by year. If your deadline depends on holidays, subtract them from the working-day figure yourself.

Days = (end − start) ÷ 86,400,000 ms · Result date = start + offset days

  • Start / end — the two dates being compared; the end date is not counted itself
  • Working days — Monday to Friday within the period, ignoring public holidays
  • Offset — days added to the start date, negative to count backwards

Worked example

From 2026-01-15 to 2026-08-02, with a 45-day offset

Inputs

Start2026-01-15
End2026-08-02
Offset+45 days

Results

Days between199
Working days142
Start + 45 days2026-03-01

199 days is a little over 28 weeks, of which 57 fall on a weekend — which is why a deadline quoted in working days always arrives later than it sounds.

Frequently asked questions

Is the end date included in the count?

No. From the 1st to the 2nd counts as one day, which is the convention for interest, notice periods and rental terms. Add one if you need to count both endpoints inclusively.

Are public holidays excluded from working days?

No — only weekends. Holidays differ by country, state and year, so subtract your own from the working-day figure.

How are leap years handled?

Automatically. The calculation works on actual elapsed time, so any 29 February inside the range is counted like any other day.

Is my data sent anywhere?

No. The calculation runs entirely in your browser. Nothing you type is transmitted to us or stored.

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