How do I use the Date ± Days Calculator?
Enter your values in the fields and the result updates instantly as you type.
Date ± Days Calculator
Add or subtract days from a date. Enter your values, review the formula, and use the worked result as a quick check for everyday planning.
Date ± Days Calculator
Add or subtract days from a date.
Format: YYYY-MM-DD (Year-Month-Day)
Use negative for subtraction
Results
Result date
2024-01-31
Day of week
Wednesday
Formula: New Date = Start Date ± Days
Date Calculator: Add or Subtract Days
Find what date falls a specific number of days before or after a given date. Useful for project deadlines, contract terms, pregnancy tracking, and event planning.
Formula
New Date = Start Date ± Number of Days. Enter a positive number to move forward in time, or a negative number to move backward. The calculator accounts for leap years and varying month lengths automatically.
Worked example
Starting from January 15, 2024 and adding 45 days: result is February 29, 2024 (a leap year). Subtracting 30 days from March 10 gives February 9.
Practical guidance
Project planning
When a contract says "delivery within 30 business days," use this calculator to find the calendar deadline. Remember that business days exclude weekends and holidays — this tool calculates calendar days.
Leap year awareness
The calculator automatically handles February 29 in leap years. If you add 1 day to February 28 in a leap year, you get February 29, not March 1.
Frequently asked questions
What formula does this calculator use?
New Date = Start Date ± Days
Can I use decimal values?
Yes. Decimal inputs are supported for most calculators. Integer-based tools use rounded integer values where appropriate.
Is this calculator free?
Yes. CalcuNimble calculators are free and optimized for fast everyday use.