About this Add or Subtract Days Calculator
Add or Subtract Days Calculator is a quick calendar utility for moving forward or backward by an exact number of days.
Formula or method
Target date = Start date + signed number of calendar days.
Example
Adding 10 days to January 1 produces January 11.
Common uses
- Find a date several days in the future.
- Subtract days to determine an earlier date.
- Check deadline offsets.
How to use this tool
- Enter the values or text requested by the calculator.
- Choose units or options when the tool provides them.
- Select the calculation button and review the result.
- Use the formula, example and notes on this page to check whether the result fits your situation.
Important note
The calculation uses calendar days, including weekends and holidays.
Frequently asked questions
How do I subtract days?
Enter a negative number, such as -30.
Are weekends skipped?
No. Every calendar day is counted.