Add/Subtract Days Calculator
Add or subtract a given number of days from a starting date to find the resulting date.
Resulting date
Your result will appear here.
What is Add/Subtract Days Calculator?
Add/Subtract Days Calculator determines the exact future or past date resulting from adding or subtracting a given number of days from any starting date. It reliably handles varying month lengths, year turnovers, and leap years.
How to use Add/Subtract Days Calculator
- 1Choose whether you want to Add days or Subtract days using the mode selector.
- 2Select your starting date.
- 3Enter the number of days you want to add or subtract.
Key features
Bidirectional Add and Subtract Modes
Easily switch between adding days to project future dates or subtracting days to find historical dates.
Handles Month & Leap Year Transitions
Transitions accurately across month ends (28, 29, 30, 31 days) and leap years.
Formatted Date Readout
Displays the resulting date with day of the week, full month name, date, and year.
100% Client-Side Processing
Evaluates dates entirely in your local browser without external network requests.
Examples & use cases
90-Day Warranty Expiration
Add 90 days to October 15, 2026
Mode: Add, Date: 2026-10-15, Days: 90
Wednesday, January 13, 2027
30-Day Prior Notice Check
Subtract 30 days from March 1, 2024 (leap year)
Mode: Subtract, Date: 2024-03-01, Days: 30
Wednesday, January 31, 2024
Frequently asked questions
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