Skip to content

Date Addition Calculator

Add or subtract days, weeks, months or years from a date, with an option to count business days.

Loading tool

This tool runs in your browser. Nothing is uploaded.

About Date Addition Calculator

Date Addition Calculator finds the date that falls a given number of days, weeks, months or years before or after a starting date, and can skip weekends for business-day deadlines.

For notice periods, delivery estimates, visa stays, and payment terms such as net 30.

What it does

  • Add or subtract
  • Days, weeks, months or years
  • Business-day mode skips Saturdays and Sundays
  • Month-end dates clamped correctly

How to use Date Addition Calculator

  1. Pick a start date.
  2. Choose add or subtract, then the amount and unit.
  3. Tick business days if weekends should not count.
  4. Read the resulting date and weekday.

Frequently asked questions

What is 31 January plus one month?

The result is clamped to the last day of February, which is the usual convention for contracts and billing.

Are public holidays skipped in business-day mode?

No. Only weekends are skipped, because holidays differ by country and region.

Limits and privacy

Public holidays are not excluded.

Everything happens on your device, so your content never reaches our server.

Date Difference CalculatorCount the days, weeks, months and business days between two dates.In browserAge CalculatorWork out exact age in years, months and days, plus the days until the next birthday.In browserSimple Interest CalculatorCalculate simple interest and the total amount using I = P × r × t.In browser