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The weekday updates as you type. Every date from year 1 to 9999 is supported, with clear messages for impossible dates like February 30.
Any date from year 1 to 9999
Day of the Week Calculator
Find out what day of the week any date falls on. Check what day you were born, plan an event or settle a trivia question, then see the same date in future years with a calendar view and the step-by-step Doomsday method.
- Instant answer
- Birthday insights
- Interactive calendar
- Shows the working
Find the day of the week for any date
Pick a date
Enter any date from year 1 to 9999.
Quick dates
October 2026
Day of the week
October 13, 2026 is a Tuesday.
That is today.
- Day of the year
- 286
- ISO week
- 42
- Quarter
- Q4
- Days in month
- 31
- Leap year
- No
- Days from today
- 0
Folklore says: Tuesday’s child is full of grace.
This date in the next 10 years
How it was calculated (Doomsday method)
Why it is better
More than a weekday lookup
Most day of the week calculators return one word. This one gives you the weekday plus the context you actually wanted, in a clean tool that works on any phone.
Interactive calendar
See the whole month with weekends highlighted. Tap any day or jump a month forward or back to explore nearby dates.
Birthday insights
Find the day you were born, how many days ago it was and which of your next 10 birthdays land on a weekend.
Same date in future years
Plan anniversaries, weddings and recurring events by seeing which weekday the date falls on for the next decade.
Learn the Doomsday trick
Each answer comes with the Doomsday method worked out, so you can learn to find any weekday in your head.
Share any date
Copy the answer or a link that opens with your date loaded. It is a quick way to settle a debate or send event details.
How to use
How to use the day of the week calculator
You can get an answer in under five seconds. Here is how.
Enter the date
Type the day and year, then pick the month. You can also tap a quick date or choose a day on the calendar.
Read the weekday
The day of the week appears instantly, along with a sentence that says whether the date was, is or will be that day.
Explore the details
Check the day of the year, ISO week number, quarter and how far the date is from today.
Plan ahead
Use the list of the next 10 years to see when the date falls on a weekend, then share or copy the result.
The method
How to calculate the day of the week for any date
The easiest mental method is the Doomsday rule, created by mathematician John Conway. In any year, a set of easy-to-remember dates all fall on the same weekday, called that year’s doomsday.
These dates are 4/4, 6/6, 8/8, 10/10 and 12/12, plus 5/9, 9/5, 7/11 and 11/7. In January the doomsday is the 3rd (the 4th in leap years), in February it is the last day, and in March it is the 14th.
doomsday = (century anchor + ⌊yy/12⌋ + yy mod 12 + ⌊(yy mod 12)/4⌋) mod 7Century anchors: 1800s Friday, 1900s Wednesday, 2000s Tuesday, 2100s Sunday. yy is the last two digits of the year.
Once you know the doomsday, count forward or back from the nearest doomsday date in your month. Computers often use Zeller’s congruence instead, which turns the same idea into a single formula. To count the days between two dates, try our date calculator.
Worked example
What day was July 20, 1969?
- The 1900s anchor is Wednesday (3).
- For yy = 69: 69 ÷ 12 = 5 remainder 9, and 9 ÷ 4 = 2.
- Add them: 3 + 5 + 9 + 2 = 19, and 19 mod 7 = 5, so the doomsday of 1969 is Friday.
- July’s doomsday is 7/11, a Friday. July 20 is 9 days later, and 9 mod 7 = 2.
- Friday plus 2 days is Sunday.
Apollo 11 landed on the Moon on aSunday
Folklore
What day were you born? The Monday’s Child rhyme
Many people want to know their birth weekday because of the traditional English rhyme “Monday’s Child”, first recorded in 1838. It links each day to a personality trait. It is folklore rather than science, but it is a fun way to describe yourself.
| Born on | Line from the rhyme | In plain words |
|---|---|---|
| Monday | Monday’s child is fair of face | Good-looking |
| Tuesday | Tuesday’s child is full of grace | Graceful and kind |
| Wednesday | Wednesday’s child is full of woe | Deep and thoughtful |
| Thursday | Thursday’s child has far to go | Ambitious, will travel far |
| Friday | Friday’s child is loving and giving | Warm and generous |
| Saturday | Saturday’s child works hard for a living | Hardworking |
| Sunday | The child born on the Sabbath day is bonny and blithe, good and gay | Cheerful and good-natured |
Reference
Famous dates and their days of the week
Here are the weekdays of some well-known historical and upcoming dates. Select Load to open any of them in the calculator.
| Event | Date | Day of the week | Action |
|---|---|---|---|
| US Declaration of Independence | July 4, 1776 | Thursday | |
| Wright brothers’ first flight | December 17, 1903 | Thursday | |
| Titanic sinks | April 15, 1912 | Monday | |
| VE Day, end of World War II in Europe | May 8, 1945 | Tuesday | |
| India’s Independence Day | August 15, 1947 | Friday | |
| India becomes a republic | January 26, 1950 | Thursday | |
| Apollo 11 Moon landing | July 20, 1969 | Sunday | |
| Fall of the Berlin Wall | November 9, 1989 | Thursday | |
| Start of the year 2000 | January 1, 2000 | Saturday | |
| September 11 attacks | September 11, 2001 | Tuesday | |
| Christmas 2026 | December 25, 2026 | Friday | |
| Next leap day | February 29, 2028 | Tuesday |
Calendar facts
Surprising facts about weekdays and calendars
The Gregorian calendar follows neat patterns. Knowing them helps you check any answer.
Calendars repeat
Between 1901 and 2099, a year’s calendar can be reused after 6, 11 or 28 years. A leap-year calendar only comes back every 28 years.
A 400-year cycle
The full Gregorian pattern repeats every 400 years. That is 146,097 days, which is exactly 20,871 weeks.
Friday the 13th
Every year has at least one Friday the 13th and at most three. In fact, the 13th is slightly more likely to be a Friday than any other day.
The 1582 switch
The Gregorian calendar began in October 1582. Britain and its colonies switched in 1752, so older records may use the Julian calendar.
Benefits
Who uses this day of the week calculator
It is free, private and works offline once loaded. Here are the most common reasons people use it.
Curious minds
Find the day you were born, the weekday of a parent’s birthday or the day a favorite event happened.
Event planners
Check whether a wedding, party or launch date lands on a weekend, and compare the same date across several years.
Historians and genealogists
Confirm the weekday of old records, letters and family events, with a note for dates before the Gregorian switch.
Students and teachers
Practice the Doomsday rule and modular arithmetic, with every step shown so you can check your mental math.
FAQ
Day of the week calculator FAQs
What day of the week was I born?
Enter your date of birth in the calculator above. It shows the weekday instantly, how many days ago that was, and which weekday your next 10 birthdays will fall on.
How do you calculate the day of the week for any date?
Use the Doomsday method. First find the year’s doomsday from the century anchor and the last two digits of the year. Then count from the nearest doomsday date in that month, such as 4/4, 6/6 or 10/10. The calculator shows these steps for every date.
What day was January 1, 2000?
January 1, 2000 was a Saturday. The year 2000 was also a leap year, because century years divisible by 400 are leap years.
How often does a calendar repeat?
Between 1901 and 2099, a calendar can be reused after 6, 11 or 28 years. Leap-year calendars only repeat every 28 years. The complete Gregorian pattern repeats every 400 years.
Does this calculator work for dates before 1582?
Yes, but it uses the proleptic Gregorian calendar, which applies today’s rules to earlier years. Many places used the Julian calendar before 1582, and Britain switched in 1752, so historical documents may show a different weekday.
What is the Doomsday rule?
It is a mental math method devised by mathematician John Conway. Dates such as 4/4, 6/6, 8/8, 10/10 and 12/12 always share the same weekday within a year, called the doomsday. From there, any other date is a short count away.
Why does every year have a Friday the 13th?
Across the 12 months of any year, the 13th lands on every day of the week at least once. As a result, every year has at least one Friday the 13th and at most three.
What day will my birthday be next year?
Your birthday usually moves forward by one weekday each year, or by two when a February 29 falls in between. Enter your birthday above to see the exact weekday for each of the next 10 years.
Any date, any year
Know the day before you plan
From your birthday to a wedding date years ahead, this day of the week calculator gives you the answer, the calendar and the method in one place. Try another date now.
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