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Add or subtract days from a date

Find the date a number of days before or after a starting date.

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Need Resulting date? The Add or subtract days from a date derives it from Start date, Days to add (− to subtract) in one step. For instance, with Start date = 1985-03-20 and Days to add (− to subtract) = 30 it returns Resulting date = 19/04/1985.

How to use it

  1. Enter your values: Start date, Days to add (− to subtract).
  2. Read the result instantly: Resulting date.

Frequently asked questions

How does the Add or subtract days from a date work?

It takes Start date and Days to add (− to subtract) and derives Resulting date from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

2 values: Start date and Days to add (− to subtract). Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Start date = 1985-03-20 and Days to add (− to subtract) = 30, the calculator returns Resulting date = 19/04/1985. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

When would I actually use this?

Answering a scheduling question exactly: how many working days until a deadline, what date falls sixty days out, and what time that is for a colleague elsewhere.

What is the most common mistake?

Counting days by subtracting dates and forgetting whether the endpoints are included. Inclusive and exclusive counts differ by one, which is the difference between meeting a deadline and missing it.

What is the difference between the Add or subtract days from a date and the Add business days calculator?

Both return Resulting date. What differs is what they ask for: this one wants Days to add (− to subtract), the Add business days calculator wants Business days to add. Use whichever matches the numbers you already have.

Is there a tool for the next step?

Days until date calculator is the closest one after this: Count the number of days from today until a future date.

What else is worth having open alongside it?

Business days calculator and Age in days calculator — they come up in the same task often enough to be worth a second tab.

Where do the figures come from, and how current are they?

Calendar arithmetic follows the proleptic Gregorian calendar and the IANA time-zone database, so daylight-saving transitions and leap years are handled. Public holidays vary by country and region and are not assumed.

Further reading

All guides →
How-toHow to Add or Subtract Days from a DateCount forward to add, backward to subtract, rolling over month ends. Here's how, why month lengths and leap years trip you up, and when weekends count.How-toHow to Add and Subtract Time (Hours and Minutes)Add and subtract hours and minutes reliably. Learn to carry over 60, borrow when subtracting, and handle a result that crosses midnight into the next day.How-toHow Many Days Until a Date? (With Worked Examples)Count the days until any future date, understand inclusive vs. exclusive counting, and build an accurate countdown you can trust.ExplainerHow Many Working Days Are There in a Year?A year has roughly 260 weekdays before holidays. Learn where that number comes from, why it varies by country, and how public holidays bring it down to the working days you actually get.How-toHow Many Days Between Two DatesSubtract the earlier date from the later, minding month lengths and leap years. Here's how to count it, and whether to include both endpoints.How-toHow to Count Business DaysBusiness days are weekdays minus holidays. Here's what counts, how to work them out between two dates, why holidays complicate it, and where it matters.