How to add or subtract days from a date
- Pick the Start date. It starts on today.
- Choose Add or Subtract and fill in any mix of Years, Months, Weeks and Days. Leave the rest at 0. For business deadlines, switch Count to Working days, which skips Saturdays and Sundays.
- Read the new date and its day of the week, plus the number of days and weeks between the two dates.
Worked examples
| Start date | Change | Result |
|---|---|---|
| 1 March 2026 | add 90 days | Saturday, 30 May 2026 |
| 1 December 2026 | subtract 6 weeks | Tuesday, 20 October 2026 |
| 31 January 2026 | add 1 month | Saturday, 28 February 2026 |
| 31 March 2026 | subtract 1 month | Saturday, 28 February 2026 |
| 30 January 2026 | add 1 month and 1 day | Sunday, 1 March 2026 |
Years and months are applied first, then weeks and days. That order matters at the end of a month. In the last row 30 January plus 1 month is 28 February, and one more day makes 1 March. Adding the day first would give 31 January plus 1 month, which is 28 February.
Under the result you also get the date in YYYY-MM-DD form, the total number of days between the two dates and the same gap in weeks. Only whole numbers work in the boxes. For half a week, enter 3 or 4 days instead.
Calendar days, not working days
Every day counts here, weekends and public holidays included. That matches most deadlines written in days, such as a 30-day return window or a 14-day cooling-off period. Some legal and payment deadlines use business days instead, and those skip weekends and holidays.
To see how many weekdays sit between two dates, use the days between dates calculator. It counts Monday to Friday separately. Holidays differ by country, so take off any that fall in your range yourself.