Days Calculator
What the Days Calculator answers
Days Calculator answers "what date is X days before or after another date?" — starting from a single date, it adds or subtracts a number of days to give you a new date. It has two modes: add or subtract a number of days from a date you pick, or find the date a specific number of days from a given date (using a negative number to go backward instead of forward).
How to add days to a date
In "Add/subtract days" mode, pick a date, choose Add, and enter how many days — the result is the new date. Adding 30 days to today, for example, gives the exact calendar date 30 days out, correctly crossing month or year boundaries where needed.
How to subtract days from a date
The same mode works in reverse — pick a date, choose Subtract, and enter how many days. Subtracting 90 days from today lands on the exact date 90 days earlier, month and year boundaries included.
Finding a date X days from today
"X days from a date" starts from a date you pick (defaulting to today) and shifts by however many days you enter — a positive number gives a future date, a negative number gives a past date. This is the faster mode when you already know today's the starting point and just want the resulting date, without switching Add/Subtract.
Calendar details
Every date calculation uses the real calendar, not a simplified fixed-length month — so adding or subtracting days across months with 28, 29, 30, or 31 days always lands on the correct real-world date, and leap years (like a span that crosses February 29th) are handled automatically. A calculation that crosses December 31st correctly rolls into the next year, and one that crosses January 1st correctly rolls back into the previous year.
Days Calculator vs. Timespan Calculator
These two tools answer opposite questions. Days Calculator takes one date and a number of days, and gives you a new date. If you instead have two dates and want to know the difference between them — in days, weeks, months, or years — that's Timespan Calculator.
Common use cases
- Finding a deadline that's a set number of days from today
- Working out a due date, renewal date, or follow-up date
- Finding what date was a given number of days in the past
- Planning a date a fixed number of days before an event, like a shipping cutoff
Frequently asked questions
What date is 30 days from today?
Use "X days from a date" with today's date already filled in, enter 30, and the result shows the exact date 30 days later.
How do I subtract 90 days from a date?
Either enter -90 in "X days from a date," or use "Add/subtract days" mode, pick your date, choose Subtract, and enter 90.
Does it account for leap years?
Yes — dates are calculated using real calendar math, so a leap year's February is correctly treated as 29 days.
Does it count weekends?
This calculator counts every calendar day, weekends included. If you specifically need weekdays only, Timespan Calculator's "Business days" mode excludes weekends (though not public holidays).