Everyday

Date Difference Calculator

The days between two dates — as days, weeks, months, and working days with the weekends taken out.

Pick a start date and an end date.

Start date

End date

Exact calculation. Given your inputs, this is the answer — no estimation involved.

How this calculator works

Counting days between dates sounds trivial and is a classic source of off-by-one and off-by-a-day errors. Two dates one day apart can be 23 or 25 hours apart in local time, because clocks change twice a year — so dividing elapsed time by 24 hours quietly loses or gains a day depending on the season. Everything here is calendar arithmetic in UTC, which has no such gaps.

There are two right answers to "how many days from Monday to Friday". Four, if you count the gaps between them. Five, if you count the days themselves — which is what a hotel bills you for, what a contract runs for, and what a holiday request uses. Neither is more correct, so both are shown rather than one being picked silently.

Years and months are counted against the calendar rather than divided out. "One year and two months" has no fixed length: it depends entirely on which year and which months, so the only correct method is to walk the calendar forward the way you would on paper.

Working days remove Saturdays and Sundays. They do not remove public holidays, because those vary by country, by state and by year — a calculator that quietly assumed one jurisdiction would be wrong for nearly everyone using it.

The formula

Exactly what happens to your numbers, step by step.

Days between
```
days = (end − start) in whole UTC days
```
UTC because every UTC day is exactly 24 hours. Local days are not, twice a year.
The two counts
```
exclusive = days
inclusive = days + 1
```

Working days

working = inclusive days − Saturdays and Sundays

A worked example

Thursday 10 September 2026 to Wednesday 16 September 2026.

What you enter

Start: 2026-09-10 (Thursday)
End: 2026-09-16 (Wednesday)

The working

Days between: 6
Counting both days: 7
Weekend days in the range: 2
Working days: 7 − 2 = 5

6 days apart · 5 working days

Six and seven are both correct, for different questions. If you are booking a hotel it is six nights; if you are counting how many days you will be away it is seven. The gap between those two numbers is where most date mistakes live.

Assumptions

Every result here rests on these. Change your inputs and the result changes with them.

Dates are whole calendar days, in UTC, with no time of day.
Working days are Monday to Friday.
Weekend counts are inclusive of both the start and end dates.

What this cannot tell you

Public holidays are not deducted. They differ by country, by state or region, and by year, and there is no honest single answer — check the relevant public calendar and subtract them yourself.
It does not handle times of day. Two dates are compared as whole days, so it cannot tell you the hours between 9am Monday and 2pm Wednesday.
Time zones are not modelled. If a deadline is set in one zone and you are in another, the date can differ by one at either end.
Business-day conventions vary. Some contracts count Saturday as a working day, and finance uses several different day-count conventions that this does not implement.

Questions people ask

How many days are between two dates?

Subtract the earlier from the later in whole days — but decide first whether you are counting the gaps or the days themselves. Monday to Friday is four gaps and five days. Both figures are shown above so you can take whichever your question needs.

Should I count the first and last day?

It depends what you are counting. Hotel nights, notice periods and interest days usually count the gaps. Holiday allowance, event lengths and how long you will be away usually count both endpoints. The difference is exactly one day, and it is the most common date error there is.

Does it account for leap years?

Yes, exactly. It counts real calendar days, so any 29 February inside the range is included automatically. A year is 365 or 366 days depending on which year it is, not 365.25.

Why does it not subtract public holidays?

Because there is no honest way to. They vary by country, by state and by year, and several move around — Easter is different every year, and some countries move a holiday when it falls on a weekend. Deducting a guessed set would be worse than showing you the weekday count and letting you subtract the ones that actually apply.

Why do some date calculators give a different answer?

Almost always the inclusive-versus-exclusive question, and occasionally a time zone. A calculator that works in local time and divides elapsed hours by 24 can also be off by a day across a clock change. This works in whole UTC calendar days, which sidesteps that entirely.

Sources and review

This calculator uses standard arithmetic with no external rules or published rates, so there is nothing to cite beyond the formulas shown above.

Methodology version 1.0.0 · Last reviewed September 10, 2026