Day of the Week

Find out which day of the week any date falls on, with the day number, week number and how far away it is.

Pick any date and see which day of the week it lands on, plus where it sits in the year.

That date is a

—

  • —Day of the year
  • —ISO week
  • —Days from today
  • —Days left in year

    How Does It Work?

    1. Choose a dateAny date, past or future. The box starts on today so checking "what day is it" takes no clicks at all.
    2. Read the weekdayThe day name appears immediately, with the full written date underneath.
    3. Use the extra detailDay of the year, ISO week number and the distance from today are shown for planning and for filling in forms.

    What Is It Used For?

    The Gregorian calendar repeats on a 400-year cycle, so every date has a fixed weekday that can be worked out exactly. That matters for birthdays, historical dates, contract dates that must not fall on a weekend, and any planning that depends on week numbers.

    • Finding out what day of the week you were born on.
    • Checking whether a deadline or delivery date falls on a weekend.
    • Converting a date into an ISO week number for a work schedule or timesheet.
    • Planning an event and seeing how many days remain.
    • Checking a historical date for a document or a family tree.

    Examples

    DateWeekdayNote
    1 January 2026ThursdayDay 1 of 365
    29 February 2024ThursdayLeap day
    25 December 2026FridayDay 359
    20 July 1969SundayApollo 11 Moon landing

    Frequently Asked Questions

    How do I find what day of the week a date was?

    Enter the date above. The calculation uses the Gregorian calendar, including leap year rules, so it is exact for any date from 1583 onwards.

    What is an ISO week number?

    A numbering of the weeks of the year where weeks start on Monday and week 1 is the week containing the first Thursday of January. Businesses across Europe use it for planning, so a date can occasionally fall in week 1 of the following year.

    Which years are leap years?

    Years divisible by 4, except century years that are not divisible by 400. So 2024 and 2000 were leap years, but 1900 and 2100 are not.

    Does it work for dates before 1583?

    It applies Gregorian rules to any date you enter, but most of Europe used the Julian calendar before October 1582, so early dates will not match historical records.

    How do I count days between two dates instead?

    Use the Days Between Dates tool, which gives the gap in days, weeks and months.

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

    Days Between Dates

    Count the days, weeks and months between any two dates.

    Date After X Days

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