Add / Subtract Days Calculator
Need to know what date it is 30 days from now? Or 90 days before a deadline? Pick a starting date, enter the number of days to add or subtract, and get the resulting date instantly.
How to use
- Pick a starting date. It defaults to today but you can change it.
- Enter how many days you want to add or subtract.
- Choose whether you're going forward or backward.
- Hit Calculate to see the exact resulting date.
Related tools:
Adding or subtracting days from a date by hand works fine for a few days but breaks down quickly for larger numbers - especially when months have different lengths and leap years are involved. Enter a start date and a number of days and the calculator gives the exact resulting date, handling February, month-end rollovers, and year boundaries automatically.
Practical uses come up constantly: what is the date 90 days from a contract signing, when does a 30-day return window close, what date is 6 weeks from today for a project deadline. The tool also works in reverse - subtract days to find what date something was in the past.
Frequently Asked Questions
Does this account for leap years?
Yes. The calculator uses the full calendar including leap years. February 29 is handled correctly whether the year is a leap year or not - adding 1 day to Feb 28 in a leap year gives Feb 29, and in a non-leap year gives March 1.
Can I calculate business days instead of calendar days?
This calculator adds or subtracts calendar days (every day counts). For business day calculations that skip weekends, use the Business Days Calculator.
What is the maximum number of days I can add?
There is no practical limit. You can add thousands of days to project far into the future or subtract to go far into the past.