Date After X Days

Find the date a given number of days, weeks or months from a start date — forwards or backwards, calendar days or working days.

Pick a starting date, say how far to move and in which direction, and get the exact date — including which day of the week it lands on.

Resulting date

    How Does It Work?

    1. Choose the start dateIt defaults to today, so "90 days from today" takes one edit.
    2. Set the amount and unitDays, working days, weeks, months or years. Months and years keep the same day number where possible.
    3. Pick a directionAdd to look forward, subtract to look back at when something must have started.

    What Is It Used For?

    Deadlines are usually expressed as a period rather than a date: 30 days to pay, 14 days to return, 90 days probation. This tool converts that period into the actual calendar date, and tells you the weekday so you can spot a deadline falling on a Sunday.

    • Finding the due date of a 30-day invoice.
    • Working out the last day of a 14-day return window.
    • Setting the end of a probation or notice period.
    • Counting forward in working days for a service level agreement.
    • Looking backwards to find when a countdown must have started.

    Examples

    StartMoveResult
    1 Jan 2026+30 calendar days31 January 2026
    1 Jan 2026+30 working days12 February 2026
    31 Jan 2026+1 month28 February 2026
    15 Mar 2026−90 days15 December 2025

    Frequently Asked Questions

    What date will it be in 30 days?

    Leave the start date as today, enter 30, keep the unit on calendar days and the answer appears with its weekday.

    How are months added?

    The day number is kept where possible. Adding one month to 31 January gives 28 February (or 29 in a leap year), because February has no 31st. This matches how contracts are normally read.

    What counts as a working day here?

    Monday to Friday. Public holidays are not deducted — if you need those, count the range in the Working Days Calculator instead.

    Can I go backwards?

    Yes. Switch the direction to "Before (subtract)" and the calculator counts back from your start date.

    Does it handle leap years?

    Yes. Day arithmetic uses real calendar dates, so 29 February is included whenever it falls inside the range.

    Free. No registration. This tool runs entirely in your browser, so the data you enter stays on your device.