Date calculator
A date calculator finds the date a number of days, weeks, months or years before or after a start date, or counts the days between two dates. Months follow the EDATE rule (January 31 plus one month is the last day of February), and business-day mode skips weekends and, if you choose, US federal holidays.
Common calculations from today
Counted from today, Sunday, November 15, 2026. Each link opens a page with more detail and a spreadsheet formula.
| Calculation | Date |
|---|---|
| 7 days from today | Sunday, November 22, 2026 |
| 14 days from today | Sunday, November 29, 2026 |
| 30 days from today | Tuesday, December 15, 2026 |
| 45 days from today | Wednesday, December 30, 2026 |
| 60 days from today | Thursday, January 14, 2027 |
| 90 days from today | Saturday, February 13, 2027 |
| 180 days from today | Friday, May 14, 2027 |
| 1 month from today | Tuesday, December 15, 2026 |
| 3 months from today | Monday, February 15, 2027 |
| 6 months from today | Saturday, May 15, 2027 |
| 1 year from today | Monday, November 15, 2027 |
| 30 days ago | Friday, October 16, 2026 |
| 90 days ago | Monday, August 17, 2026 |
How it's worked out
Adding or subtracting works in two steps. Years and months go first, as whole calendar months (a year is 12 of them): the day number stays put and only the month and year move. If that day doesn't exist in the month you land in, you get the month's last day instead, so a month after January 31 is the last day of February. Weeks and days are then added or taken away as exact counts, seven days to a week.
Leap years follow the same rule. February 29 plus one year is February 28, because the next year has no February 29. Adding days needs no special handling, since every real day on the calendar is counted. The start date itself is day zero: adding 1 day gives the next day.
Days between dates counts the start date but not the end date, the usual way to measure a gap, so January 1 to January 2 is 1 day. Tick "Include the end date" to count both. Whole calendar months come first, then the leftover days. Business days are the Mondays to Fridays in that span, shown with and without federal holidays.
Business days step one weekday at a time, skipping Saturdays and Sundays, until the number you entered is counted, like the WORKDAY function. If you start on a weekend, the first day counted is the next weekday (or the previous one when subtracting).
With federal holidays switched on, the 11 US federal holidays are skipped on the days they're observed. A holiday that falls on a Saturday is observed on the Friday before, and one on a Sunday on the Monday after: July 4, 2026 is a Saturday, so Friday, July 3 is the day off. Juneteenth counts from 2021, when it became a federal holiday; the other holidays follow today's rules for every year. State, local and company holidays aren't included.
In Excel or Google Sheets (start date in A1, end date in B1)
- Add 90 days:
=A1+90 - Subtract 90 days:
=A1-90 - Add 3 months:
=EDATE(A1, 3) - Add 2 years:
=EDATE(A1, 2*12) - 1 year, 2 months, 3 weeks and 4 days:
=EDATE(A1, 1*12+2)+3*7+4 - Add 10 business days:
=WORKDAY(A1, 10) - Also skip holidays listed in H1:H11:
=WORKDAY(A1, 10, H1:H11) - Days between A1 and B1:
=B1-A1 - Business days, counting both dates:
=NETWORKDAYS(A1, B1)
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Frequently asked questions
What date is 90 days from a given date?
Count forward 90 calendar days, not counting the start date. From today, Sunday, November 15, 2026, 90 days later is Saturday, February 13, 2027. For any other date, set it as the start date above and tap +90 days.
How many days are there between two dates?
Subtract the earlier date from the later one. That counts the start date but not the end date: from today, Sunday, November 15, 2026, to Tuesday, December 15, 2026 is 30 days. The Days between dates tab also gives years, months and business days, and =B1-A1 does the same in a spreadsheet.
Is adding 3 months the same as adding 90 days?
Not usually. Three calendar months keeps the day number, so it covers anywhere from 89 to 92 days depending on the months involved. From today, 3 months later is Monday, February 15, 2027, while 90 days later is Saturday, February 13, 2027.
How do I add days or months to a date in Excel?
Excel and Google Sheets store dates as numbers, so =A1+90 adds 90 days and =A1-90 takes them away. For months, use =EDATE(A1, 3); it moves to the last day of the month when needed, just like this calculator, and =EDATE(A1, 12) adds a year. For business days, =WORKDAY(A1, 10) skips weekends, and =WORKDAY(A1, 10, H1:H11) also skips the holiday dates listed in H1:H11. Format the result cell as a date.
Does the calculator count the start date?
No. The start date is day zero, so adding 1 day gives the next day. In business-day mode the first day counted is the next weekday: 1 business day after a Friday, a Saturday or a Sunday is the following Monday.
What is February 29 plus one year?
February 28 of the next year, because only leap years have a February 29. EDATE gives the same answer. Add four years instead and you usually land on February 29 again; century years that aren't divisible by 400, such as 2100, are the exception.
Which holidays can business-day mode skip?
With the federal holidays option ticked: New Year's Day, Martin Luther King Jr. Day, Presidents' Day, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving and Christmas Day, each on its observed date. A holiday on a Saturday is observed the Friday before, and one on a Sunday the Monday after. State and company holidays aren't included.