Subtract Days From a Date
Subtract days, weeks, months or years from a date
Enter a start date, a number and a unit, and the calculator returns the date that number of days, weeks, months or years earlier, with the weekday, the ISO week and the number of business days in between. Today is Saturday, October 3, 2026. Worked out from today: 30 days before today is Thursday, September 3, 2026; 60 days before today is Tuesday, August 4, 2026; 90 days before today is Sunday, July 5, 2026; 180 days before today is Monday, April 6, 2026; 6 months before today is Friday, April 3, 2026; 1 year before today is Friday, October 3, 2025.
How months and years are handled
Days and weeks are exact. Months and years follow the calendar: the same day of the month is kept, and if that day does not exist in the target month the last day of the month is used. January 31 plus one month is February 28, or February 29 in a leap year, and February 29 plus one year is February 28. Adding a month and then taking one away therefore does not always return to the start date, which is normal for calendar arithmetic and matches spreadsheet functions such as EDATE.
When to use it
Typical questions are: what date is 90 days after an invoice, when does a 30-day return window end, what is six months before a due date, when does a one-year warranty expire, or what date was 100 days ago. For deadlines counted in business days, use the business days calculator instead, because it skips weekends and federal holidays.
Frequently asked questions
How do I add days to a date?
Enter the start date, the number of days and press Calculate.
How do I subtract days from a date?
Use the subtract page or choose subtract in the form.
Is the start date counted?
No. The start date is day zero.
How are months added?
The same day of the month is kept, using the last day if the month is shorter.
What is January 31 plus one month?
February 28, or February 29 in a leap year.
What is February 29 plus one year?
February 28 of the next year.
Does it handle leap years?
Yes.
Can I add weeks?
Yes. A week is seven days.