How do I find the date a number of days from today?
To find a date a set time away, add or subtract years and months first, then weeks and days, using the last day of a shorter month if the original day does not exist there. Enter a start date, direction and years, months, weeks or days in FixDoks's Add Days to Date calculator to see the date and weekday.
Add Days to Date at a glance
| Inputs | Start date, add or subtract, years/months/weeks/days, business days option |
|---|---|
| Output | Resulting date and weekday |
| Processing | In your browser; your files are not uploaded |
| Price | Free |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use Add or Subtract Days from a Date
- Pick a start date. It defaults to today.
- Choose Add or Subtract, and Calendar days or Business days.
- Enter the years, months, weeks and days.
- Read the resulting date and its weekday.
How does date addition work?
Adding days is simple: count forward one calendar day at a time. Adding months is trickier because months have different lengths. The calculator adds years and months first, then weeks and days. If the start day does not exist in the target month, it uses the last day of that month. For example, 31 January plus 1 month gives 28 February (or 29 February in a leap year), not 3 March.
Worked example
What date is 90 days after 26 September 2026?
- 4 days take you to 30 September
- 31 more days take you to 31 October (35 days)
- 30 more days take you to 30 November (65 days)
- 25 more days take you to 25 December 2026, a Friday (90 days)
Business days
Choose Business days to skip Saturdays and Sundays. Adding 10 business days to a Friday lands on the Friday two weeks later. Public holidays are not skipped, so if a holiday falls in the period, add one more day for each. Many legal and banking timelines, such as "within 7 working days", are counted this way.
Common uses
- Deadlines: 30, 60 or 90 days from an invoice date, a notice, or an order.
- Return and warranty windows: 7, 10 or 30 days from delivery.
- Visa and stay limits: 90 or 180 days from arrival.
- Pregnancy: 280 days (40 weeks) from the first day of the last period gives the usual estimated due date. Your doctor's scan-based date takes priority.
- Subtracting: the last date to apply if an event needs 45 days' notice.
- Medicine courses, loan moratoriums and probation periods.
Weeks and months are different
"12 weeks" is always 84 days, but "3 months" can be 89, 90, 91 or 92 days depending on the months involved. If a document says a number of days, enter days. If it says months, enter months, so the result lands on the same date of the later month.
Counting rules to watch
Some documents count the start day as day 1, others start counting from the next day. This tool uses the second, more common rule: adding 1 day to Monday gives Tuesday. If your rule counts the start day, subtract one day from the number you enter. Always follow the exact wording of the contract, notice or government order for legal deadlines.
To go the other way and count the days between two dates, use the Date Difference calculator.