Date Calculator

Written byOleh Soloninupdated 5 October 2026

From date

Leave empty for today.

Operation

How many

Of what

Result

Date2027-01-04
Day of the weekMonday
Calendar days between90

Where a deadline actually lands

Find the date a set number of days, weeks or months away. For deadlines, delivery estimates and notice periods.

'Ninety days from today' sounds simple until you have to cross two month boundaries and a leap year to answer it.

The tool moves along the real calendar, so month lengths and leap days are handled without you counting on your fingers.

How to use

Set the starting date, or leave it empty to count from today.
Choose Add or Subtract and the unit: days, weeks, months, years or working days.
Enter the amount and read off the date you land on, its weekday and the number of calendar days in between.

Days, months and working days from a fixed date

Each row is a separate run. Adding months keeps the day of the month where it can and clamps to the last day where it cannot, so 31 January plus a month is 28 February.

Every row comes from the calculator on this page.
Start	Change	Result	Weekday	Calendar days
2026-03-01	+ 90 days	2026-05-30	Saturday	90
2026-01-31	+ 1 month	2026-02-28	Saturday	28
2026-09-22	+ 10 working days	2026-10-06	Tuesday	14
2026-09-22	− 280 days	2025-12-16	Tuesday	280

What this calculator shows

The resulting date after adding or subtracting your interval
The day of the week it falls on
Correct rollover across months and years

What to keep in mind

Adding calendar days includes weekends and public holidays.
Adding months clamps to the end of the month — 31 January plus one month gives 28 or 29 February.

FAQs

What is 90 days from today?

Leave the date empty to count from today and enter 90 days. It is roughly three months, but the exact date drifts depending on which months you cross.

What happens adding a month to 31 January?

You get the last day of February — the 28th, or the 29th in a leap year — since 31 February does not exist. Choose months as the unit and the calculator does this for you.

Does it skip weekends?

Not by default — it counts calendar days. Choose working days and it skips Saturdays and Sundays; public holidays are not taken out.

Can I subtract instead?

Yes. Choose Subtract to work backwards from a deadline to the date you need to start.

What date is 10 working days after 22 September 2026?

Tuesday 6 October 2026. The ten working days take 14 calendar days, because two weekends fall inside them.

What if the result lands on a weekend?

The calculator says so. 1 March 2026 plus 90 days is Saturday 30 May, for example; for a payment or filing deadline, check whether the rules move it to the next working day.

Worked example

A 90-day payment term

Input: 1 March 2026 + 90 days

Output: 30 May 2026, a Saturday

Note: The calculator flags weekend dates. If this is a payment or filing deadline, check whether it moves to the next working day.

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Result

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