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universal Date Calculator

universal

Free Date Calculator

Count the days between two dates, add or subtract time, work out an age or find a weekday — free, instant and entirely in your browser.

✓ Days, weeks, workdays✓ No account needed✓ Dates never uploaded✓ Any device
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    Weekends are Saturday and Sunday. Public holidays are not subtracted. Dates use the Gregorian calendar, years 1–9999.

    The dates you enter never leave your browser. Nothing is sent to a server and nothing is stored.

    How it works

    Three steps, no account

    Pick what to calculate

    Choose days between two dates, add or subtract time, age, or day of the week. Each tab shows only the fields it needs, and the dates start with today so you see a result at once.

    Enter your dates

    Tap the date fields and choose a date, or press Today. For adding and subtracting, enter any mix of years, months, weeks, days and workdays. The answer updates as you type.

    Read and copy the result

    The main result is shown large with a sentence explaining it, and below it the same span as years, months and days, weeks, workdays, hours and minutes. Copy it with one tap.

    Why it matters

    Dates are harder than they look

    Months have different lengths, leap years add a day, and "how many days" can mean with or without the last day. A small difference in the rule gives a different answer.

    This calculator states its rules openly. It counts the days that pass from the start date to the end date, and adds one day only if you tick the box to include the end date. Workdays are Monday to Friday, and months are added by calendar, so adding one month to 31 January gives the last day of February. Public holidays are not subtracted, because they differ by country and region.

    Use cases

    What people use a date calculator for

    Deadlines and notice periods

    Find the date that is 14, 30 or 90 days from today, or count the days left until a deadline.

    Project and work planning

    Count the workdays between two dates or add a number of workdays to a start date.

    Pregnancy, travel and events

    Count the weeks until a due date, the days until a trip or the days since an event.

    Age and anniversaries

    Work out an exact age in years, months and days, and see how many days remain until the next birthday.

    Contracts and billing

    Check the length of a contract, a trial period or a payment term in days, weeks or months.

    Weekdays and week numbers

    Find out which weekday a date falls on, its ISO week number and its day of the year.

    Under the hood

    How the calculation works

    Every date is turned into a whole number of days since 1 January 1970 using UTC, so daylight saving time never changes a result. The days between two dates are the difference of those numbers. Years, months and days are found by adding whole calendar months to the start date, shortening to the last day of a month where needed, and counting the remaining days. Workdays are the Monday-to-Friday days in the range. Dates use the Gregorian calendar for the years 1 to 9999. Everything runs locally in your browser.

    Questions

    Frequently asked questions

    Basics
    Is this date calculator really free?
    Yes. The calculator is completely free, with no limit on how many calculations you make. There is no paid tier and no feature locked behind a payment.
    Do I need an account to use it?
    No. There is nothing to sign up for, no email address to give and no login. Open the page and calculate.
    Are my dates stored or sent anywhere?
    No. All calculations run in your browser. The dates you enter are not uploaded, logged or stored by this site.
    How do I calculate the days between two dates?
    Choose the first tab, pick the start date and the end date, and the number of days appears at once. The same span is also shown as years, months and days, as weeks and days, and as workdays, hours and minutes.
    Counting and rules
    Is the end date included in the count?
    By default it is not: the count is the number of days that pass from the start date to the end date, so Monday to Friday is 4 days. Tick "Include the end date" if you also want to count the last day, which makes it 5. Contracts and leave requests often use the inclusive count, so check which one your rule means.
    How are workdays counted?
    Workdays are Monday to Friday. The calculator counts every Monday-to-Friday day in the range and treats Saturday and Sunday as weekend days. You can also add or subtract a number of workdays from a date.
    Does it take public holidays into account?
    No. Public holidays differ by country, region and year, so they are not subtracted. If holidays matter, subtract them from the workday result yourself.
    What happens when I add a month to 31 January?
    Months are added by calendar. Adding one month to 31 January gives 28 February, or 29 in a leap year, because February has no 31st day. The calculator uses the last day of the month instead of skipping into March.
    How is exact age calculated?
    Age counts complete years, then complete months, then the remaining days since the date of birth. Someone born on 15 June 1990 is 36 years, 4 months and 6 days old on 21 October 2026. A birthday on 29 February is placed on 28 February in years without a leap day.
    What is an ISO week number?
    ISO weeks start on Monday, and week 1 is the week that contains the first Thursday of the year. The first days of January can therefore belong to week 52 or 53 of the previous year, and the last days of December to week 1 of the next.
    Does it handle leap years?
    Yes. A year is a leap year if it is divisible by 4, except for century years, which must be divisible by 400. So 2024 and 2000 are leap years, while 1900 and 2100 are not. February 29 is counted correctly in every range.
    Technical
    Which dates can I enter?
    Dates from the year 1 to the year 9999 in the Gregorian calendar. The calendar is applied to all years, including those before it was introduced, so very old dates do not match historical records that used the Julian calendar.
    Do time zones or daylight saving time change the result?
    No. The calculator works with calendar dates, not clock times, and converts them to whole days in UTC. A clock change on a particular night cannot add or remove a day.
    Does it work on a phone?
    Yes. The date fields use your phone's own date picker, and the layout adapts to small screens. Once the page has loaded, the calculations also work without a connection.