How to add or subtract days
- Choose the start date. It starts with today.
- Pick Add to go forward in time, or Subtract to go back.
- Enter any mix of years, months, weeks and days, or tap a quick pick like 90 days.
- Tick Working days only if weekends should not count.
The result shows the new date, the day of the week and how many calendar days away it is.
When this comes in handy
- Payment terms: an invoice dated today with 30 day terms is due on the date shown.
- Return windows and warranties: the last day you can send something back.
- Visa and passport rules: many visas allow stays of 30, 60 or 90 days.
- Pregnancy and health: due dates are often counted as 280 days (40 weeks) from the first day of the last period. Always confirm with your doctor.
- Project planning: a task that takes 15 working days, starting next Monday.
- Looking back: what the date was 100 days ago, or 18 years ago for an age check.
How months are added
Adding a month keeps the same day number when it exists. 15 March plus one month is 15 April. When the new month is shorter, the result moves to its last day, so 31 March plus one month is 30 April. If you need an exact number of days instead, use the Days box: 30 days from 31 March is 30 April, but 30 days from 31 January is 2 March.