🗓️ Date Add/Subtract

What is Date Add/Subtract?

The Date Add/Subtract Calculator takes any start date and adds or subtracts years, months, weeks and days to show you the exact resulting date and weekday. Month-end dates are clamped automatically, so adding one month to January 31 gives February 28 (or 29 in a leap year) rather than rolling into March, and one-click presets add 30, 60, 90, 180 or 365 days from today. Everything runs locally in your browser with no account and no data upload.

How to Use Date Add/Subtract

1. Pick a start date and choose Add or Subtract
2. Enter how many years, months, weeks and days to shift
3. Read the resulting date, weekday and ISO value instantly

Why Use Our Date Add/Subtract?

• Add or subtract years, months, weeks and days in any combination from one start date
• Correct month-end clamping — no surprise rollovers for the 29th, 30th and 31st
• 30, 60, 90, 180 and 365-day presets from today for quick date questions
• 100 percent in-browser calculation with no sign-up or data leaving your device

Common Use Cases

• Working out a date 90 days from today for a deadline
• Scheduling follow-ups or renewals a set number of months out
• Backward-dating documents or planning retroactive changes

Frequently Asked Questions

• What happens when I add a month to the 31st?▾
  The date is clamped to the last day of the target month. For example, January 31 plus one month lands on February 28, and on February 29 in a leap year, instead of rolling over into March.
• Can I subtract time instead of adding it?▾
  Yes. Switch the operation from Add to Subtract and the same years, months, weeks and days are removed from the start date, with the same month-end clamping applied.
• What are the preset buttons for?▾
  The presets quickly add 30, 60, 90, 180 or 365 days to today. The 90-day button is handy for common questions like what date is 90 days from now.