What date is 90 days from today?

Enter today's date and 90 days. From 2 October 2026, for instance, it is Thursday 31 December 2026.

Is adding 30 days the same as adding a month?

No. 30 days is a fixed count; a month keeps the day of the month. From 31 January, 30 days is 2 March but one month is 28 February.

How do I add business days to a date?

Choose 'Business days' to skip weekends, or the US option to skip federal holidays as well. 2 business days after Thursday 2 July 2026 is 6 July, or 7 July skipping the observed Independence Day.

What happens if I add a month to 31 January?

February has no 31st, so the date moves to its last day: 28 February, or 29 February in a leap year. The page notes when it has done this.

What date is 6 months from today?

Choose months and enter 6: from 2 October 2026 that is 2 April 2027. Six months is not 180 days — 180 days lands on 31 March 2027.

How do I count back from a deadline?

Enter the deadline and a negative number. 21 days before 15 December 2026 is 24 November 2026.

What day of the week is a date?

Enter the date and add 0 days: the result line names its weekday. 25 December 2026 is a Friday.

Add or Subtract Days, Weeks, Months or Business Days From a Date

A date plus or minus days, weeks, months, years or business days, skipping US federal holidays if you like.

Inputs

Start date

Amount to add (+) or subtract (−)

-36,50036,500

Include CalculateEveryday mark

Result date

2026-09-29

Date: Tuesday, September 29, 2026
Working: Sunday, August 30, 2026 + 30 days
Calendar days moved: +30
Day of week: Tuesday

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What each Add or Subtract Days, Weeks, Months or Business Days From a Date input means

Start date: The date to count from: today, an invoice date, a start date.
Amount to add (+) or subtract (−): How many units to add. Use a negative number to count backwards, such as −30 for a date 30 days earlier.
Of: Days or weeks count calendar days; months and years keep the day of the month; business days skip weekends, and the US option also skips federal holidays as observed.

Add or Subtract Days, Weeks, Months or Business Days From a Date formula

days and weeks: count calendar days · months and years: move the month, keep the day (clamped to the month's end) · business days: count only Mon–Fri, minus holidays

Adding days or weeks counts calendar days, so 90 days after 2 October 2026 is 31 December. Months and years work on the calendar instead: the month moves and the day of the month stays — 15 March plus one month is 15 April — and when the target month is too short the date moves back to its last day, so 31 January plus one month is 28 February (29 in a leap year). Business days step one weekday at a time and skip Saturdays and Sundays; choose the US option to also skip federal holidays on the day they are observed. The page shows the result as a full date with its weekday, the working, and how many calendar days that moved.

Add or Subtract Days, Weeks, Months or Business Days From a Date worked example

30 days after Sunday 30 August 2026 is Tuesday 29 September 2026: the 31st of August is day 1, and 29 more days run into September. By contrast, 30 August plus one month is 30 September, and 2 business days after Thursday 2 July 2026 is Monday 6 July — or Tuesday 7 July if US federal holidays are skipped, because Independence Day falls on a Saturday that year and is observed on Friday 3 July.

More Add or Subtract Days, Weeks, Months or Business Days From a Date examples

90 days after Friday 2 October 2026: the result date is 2026-12-31, a Thursday — New Year's Eve.

5 business days after Friday 20 November 2026, skipping US federal holidays: Monday to Wednesday of Thanksgiving week count, Thursday the 26th is skipped, and Friday and the next Monday make five — 2026-11-30, ten calendar days later.

Six weeks before Friday 2 October 2026 is 2026-08-21, also a Friday: counting in weeks always lands on the same weekday.

Where the Add or Subtract Days, Weeks, Months or Business Days From a Date calculator can give the wrong answer

Months and days are different: 30 days from 31 January lands on 2 March, while one month lands on 28 February.
29 February plus one year is 28 February in a common year.
Business days here are Monday to Friday. Businesses in other countries, or with their own holiday calendars, will differ; the US option uses federal holidays only, not state or bank holidays that are not on the federal list.
Negative numbers count backwards, including business days.

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Add or Subtract Days, Weeks, Months or Business Days From a Date reference table

Common periods added to Friday 2 October 2026
Add	Result
7 days	Friday 9 October 2026
10 business days	Friday 16 October 2026
30 days	Sunday 1 November 2026
60 days	Tuesday 1 December 2026
90 days	Thursday 31 December 2026
100 days	Sunday 10 January 2027
180 days	Wednesday 31 March 2027
365 days	Saturday 2 October 2027

Source: Worked out with this page's calculator (Gregorian calendar)

Add or Subtract Days, Weeks, Months or Business Days From a Date FAQ

: Enter today's date and 90 days. From 2 October 2026, for instance, it is Thursday 31 December 2026.
: No. 30 days is a fixed count; a month keeps the day of the month. From 31 January, 30 days is 2 March but one month is 28 February.
: Choose 'Business days' to skip weekends, or the US option to skip federal holidays as well. 2 business days after Thursday 2 July 2026 is 6 July, or 7 July skipping the observed Independence Day.
: February has no 31st, so the date moves to its last day: 28 February, or 29 February in a leap year. The page notes when it has done this.
: Choose months and enter 6: from 2 October 2026 that is 2 April 2027. Six months is not 180 days — 180 days lands on 31 March 2027.
: Enter the deadline and a negative number. 21 days before 15 December 2026 is 24 November 2026.
: Enter the date and add 0 days: the result line names its weekday. 25 December 2026 is a Friday.