Date Tools

Add or subtract days

Find the date a number of calendar days before or after your chosen day.

Choose a date and offset

Date picker · 1600–2399. Results use YYYY-MM-DD.

Whole calendar days, from 0 to 292193.

Dates and day counts stay in this browser.

Your calculated date

Which date is 30 days away?

Choose a start date, then add or subtract calendar days. Zero days returns the same date.

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Find a date in three steps

  1. Choose your start date, or use your device’s today.
  2. Select Add or Subtract and enter a whole number of days.
  3. Calculate and copy the resulting date and weekday.

The 30, 60 and 90 day presets select Add and keep your chosen start date. For ordinary planning, a 30 day interval may cross into a different month.

Already know both dates? Use Date difference. For complete years, months and days since a birth date, use Age on a date.

How calendar days are counted

Are weekends and holidays included?

Yes. Every day counts, including weekends and holidays. The start date is not day 1: one day after February 28, 2024 is February 29; two days after is March 1. Subtracting one day from March 1, 2024 returns February 29. Zero days returns the start date.

What about leap years and date limits?

Calculations use the Gregorian calendar from 1600-01-01 through 2399-12-31. Leap days are counted automatically. The result must also fit this range; an out-of-range result shows an error instead of changing your input. Results use YYYY-MM-DD and an English weekday. January 1, 1970 was Thursday.

Can I calculate a business day or official deadline?

This tool counts calendar days only. It does not exclude holidays or calculate business days. Official rules can count deadlines differently; check the relevant rule for legal, financial or eligibility decisions.

Are my dates or day counts saved?

No. Dates, day counts and results stay in the page’s memory. They are never added to the URL, browser storage, analytics or feedback automatically.