DateRuler

Dates & time

Add or subtract days from a date

Quick answer: Adding days counts forward on the calendar from the start date, which itself is day 0. Example: 30 days after October 23, 2026 is Sunday, November 22, 2026, and 90 days after it is Thursday, January 21, 2027. Enter a negative number to count backward, or switch to business days to skip weekends.

  • Exact calendar math · cited sources (EIA, U.S. law)
  • Updated
  • Reviewed by Alex · How we calculate

Enter a start date and a number of days.

How to use this calculator

  1. Pick a start date (it defaults to today).
  2. Enter the number of days to add, or a negative number to subtract.
  3. Read the resulting date and the weekday it falls on.

Quick answers

Frequently asked questions

Are weekends counted?

Yes, these are calendar days. Use the business days tool to skip weekends.