What Day of the Week Is It
Find the day of the week of any date. What day of week was or will be a date
What Day of the Week Is It
How the Day of Week Calculator Works
What is the Day of Week Calculator
Our day of week calculator allows you to quickly and accurately determine what day of the week any date in history or future falls on. Simply enter the date you're interested in, and the tool will instantly show you what day of the week it was or will be.
Key Features
With our calculator you can:
- Find day of week for any date — for any date in the past or future
- Determine historical dates — find out what day of the week important events occurred
- Plan events — check the day of week for future dates
- Check weekdays/weekends — quickly determine the type of day
Practical Usage Examples
The day of week calculator is especially useful in the following situations:
- Event planning — find out what day of the week your event falls on
- Historical research — determine days of week for important historical dates
- Vacation calculations — check what days of the week your vacation includes
- Meeting organization — plan business meetings in advance
- Personal planning — find the day of week for birthdays or anniversaries
How It Works
The calculation is based on mathematical algorithms that account for the Gregorian calendar and leap years
Our calculator uses precise mathematical formulas to determine the day of week:
- Accounts for all Gregorian calendar peculiarities
- Correctly handles leap years
- Supports a wide range of dates
Interesting Facts About Days of Week
Did you know that:
- The modern seven-day week was used as far back as ancient Babylon
- A year always has 365 or 366 days, meaning the day of week shifts each year
- Any date repeats on the same day of week every 400 years
- The 13th of the month most often falls on a Friday
See Also
- Time Until Calculator - Count down the hours, minutes and seconds to a specific time
- Add or Subtract Time - Time Calculator - Add or Subtract Days, Hours and Minutes from Now
- Seconds converter - Convert Seconds to Minutes/Hours/Days/Months/Years
- Hours and Minutes in Minutes - Convert Hours and Minutes to Minutes
- Hours and Minutes as a Decimal - Convert Hours and Minutes to Decimal and Fraction
What Day of the Week Is It
This online date calculator will help you know what day of the week any date falls on. For example, it can help you find out what Day of the Week is May 17, 2021? (The answer is: Monday). Select the date you want (e.g. 'May 17, 2021') and hit the 'Find out' button.
FAQ
Which calendar is the day of the week taken from?
From the proleptic Gregorian calendar — the one in use today, extended backwards past its introduction in 1582. A date recorded in the Julian calendar (Russia kept it until 1918) will therefore show a different weekday here than it did in the records of the time.
Why does the same date fall on a different day of the week each year?
A common year is 52 weeks plus one day, so a fixed date moves one weekday forward every year, and two when a 29 February is passed. The whole cycle repeats after 28 years, except across century years that are not leap, such as 1900 and 2100.
Is there a way to find the weekday in your head?
Use the doomsday trick: within any one year the last day of February, 4 April, 6 June, 8 August, 10 October and 12 December all fall on the same weekday. For 2025 that day is Friday, so 6 June 2025 is a Friday and any nearby date is counted off from it in sevens.