Date Calculator

Count the days between two dates, or add and subtract days, weeks, months and years.

By the CalculateBright team · Updated · How we calculate

Mode
Operation
  

    How to use the Date calculator

    1. Enter your numbers. Fill in mode, start date, end date.
    2. Read your results. Results update instantly. The headline shows the days between dates; the breakdown below show the details.

    Two ways to use it

    • Days between dates counts calendar days (end date excluded, like most deadline counts) plus weeks and Monday–Friday business days.
    • Add/subtract moves a date by any combination of years, months, weeks and days. Adding a month to January 31 gives February 28 (or 29), the last valid day.

    The method

    Days = (End − Start) in calendar days
    Business days = days in (Start, End] that fall Monday–Friday

    Dates are computed in UTC so daylight saving time never shifts the count.

    Worked example

    With these inputs: modeDays between dates; start date2026-01-01; end date2026-12-31.

    The calculator gives a days between dates of 364 days (end date not included). Other results: including end date365 days, weeks52 weeks 0 days, business days (mon–fri)260, approx. months12.0.

    What your results mean

    The days-between result counts calendar days from the start date to the end date (the start date itself isn’t counted). Business days count Monday–Friday only and do not exclude public holidays.

    Tips

    • Check whether your deadline counts calendar days or business days.
    • Subtract any public holidays from business days if they apply to you.

    Frequently asked questions

    How many days are between two dates?

    Subtract the earlier date from the later one. The calculator does it for you and also shows weeks and business days.

    What date is 90 days from today?

    Choose “Add or subtract”, enter today’s date and add 90 days.

    Does the count include the end date?

    The count includes the end date but not the start date, which is the standard way to count elapsed days. Add one if you need both.

    Is the end date included?

    Not by default; the stats also show the count including the end date.

    Are holidays excluded from business days?

    No. Only weekends are excluded.

    How many days until a deadline?

    Set today as the start date and the deadline as the end date.

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