Find out which weekday any date falls on, in the past or the future.
Please enter a valid date from 1583 onward.
This tool tells you which weekday a calendar date falls on. People use it to check the weekday of a birth date, to see what day a historical event happened, to plan events and deadlines, or to settle a quiz question.
The first Moon landing took place on 20 July 1969, which was a Sunday. It was day 201 of that year. Entering the date gives the weekday and the same extra details instantly.
The Gregorian calendar has a 400-year cycle that contains exactly 146,097 days, which is exactly 20,871 weeks. That means weekdays and dates repeat in the same pattern every 400 years, and it is why a calculator can work out the weekday for any date without a lookup table. Leap years follow a simple rule: a year is a leap year if it is divisible by 4, except for century years, which must be divisible by 400. So 2000 was a leap year, while 1900 was not.
The ISO 8601 standard numbers weeks from 1 to 52 or 53. Weeks start on Monday, and week 1 is the week containing the first Thursday of the year. Many businesses and planning systems in Europe and elsewhere use these week numbers, which is why the first days of January can sometimes belong to the last week of the previous year.
Different countries switched from the Julian calendar to the Gregorian calendar at different times, starting in 1582. This tool applies the Gregorian calendar throughout, from 1583 onward. For places that changed later, such as Britain and its colonies in 1752, historical records from before their switch may show a different weekday than this tool does.
Learn why the weekday of a date is predictable, what an ISO week number means, and why some days vanished from the calendar in 1582.
Your exact age in years, months and days, with live seconds lived.
Count the time between any two dates.
A live countdown to the next birthday.
Pick the date and select Find the day. The calculator returns the weekday, plus the day of the year, ISO week number, quarter and whether the year is a leap year.
Countries adopted the Gregorian calendar at different times, from 1582 onward. This tool uses the Gregorian calendar for every date from 1583, so for places that switched later, such as Britain and its colonies in 1752, older local records may differ.
ISO 8601 weeks start on Monday, and week 1 is the week that contains the first Thursday of the year. Because of this, the first days of January can belong to week 52 or 53 of the previous year, and the last days of December can belong to week 1 of the next year.
No. A calendar date has the same weekday everywhere. Only the days from today figure depends on your device's local date.