Date & Time
Date Calculator: Add or Subtract Days
Add/subtract days, find differences between dates.
Perform arithmetic on dates.
Adding Days
Count forward, crossing month boundaries.
Finding Differences
Subtract dates. Result in days, weeks, months.
Common Uses
- Project deadlines
- Due dates
- Warranty expiration
Month Arithmetic
Jan 31 + 1 month = Feb 28/29. Month lengths vary.
Frequently Asked Questions
Add 30 days?
Count forward, crossing months as needed.
Days between dates?
Subtract, accounting for leap years.
Same day each month?
No. Jan 31 + 1mo = Feb 28/29.