Add Days Calculator — Find a Future or Past Date

What is an Add Days Calculator?

The Add Days to Date Calculator helps you find a future or past date by adding or subtracting a specific number of days from any starting date. Need to know what date it will be 90 days from now? Or what date was 60 days ago? This tool gives you the answer instantly.

It is useful for deadline planning, delivery estimates, contract expiration dates, medical follow-up scheduling, and any scenario where you need to count forward or backward from a known date.

Example: June 1 + 90 days → August 30 — also shown with the weekday (e.g., "Saturday") so you can spot weekend-sensitive deadlines at a glance.

How to Use This Calculator

Select a start date using the date picker, then enter the number of days to add. Click "Calculate Date" and the tool instantly displays the resulting date along with helpful details like the day of the week.

To subtract days, simply enter a negative number. For example, entering -14 calculates the date two weeks before your start date. The calculator handles leap years and varying month lengths automatically.

Common Uses

Deadline tracking – Find the exact date a 30-day, 60-day, or 90-day deadline falls on
Shipping estimates – Calculate expected delivery dates from order date plus transit days
Medical appointments – Schedule follow-ups that are a specific number of days after a procedure
Legal notices – Determine filing deadlines based on statutory day counts
Travel planning – Figure out return dates based on trip duration
Warranty expiry – Calculate when a warranty period ends from date of purchase

Frequently Asked Questions

Can I subtract days from a date?

Yes, enter a negative number in the days field to subtract days. For example, entering -30 will calculate the date 30 days before your chosen start date.

Does it handle leap years?

Yes, the calculator correctly accounts for leap years and varying month lengths (28–31 days) when computing the resulting date.

What is the maximum number of days I can add?

There is no practical limit. You can add thousands of days to calculate dates far into the future, or use large negative numbers to go far into the past.

Does it include the start date in the count?

The calculator adds the exact number of days to the start date. Day 0 is the start date itself, so adding 1 day gives you the next day.

What date is 90 days from today?

Select today's date, enter 90 as the number of days, and click Calculate. The result shows the exact date 90 days from now, including the day of the week.

How do I find a date 6 months from now?

To approximate 6 months, enter 182 or 183 days. For a more precise month-based calculation, try our Date Difference Calculator or Months Since Calculator.

Can I add business days instead of calendar days?

This calculator adds calendar days (including weekends). To count or add only business days, use our Business Days Calculator which excludes weekends and public holidays.