Weekday Calculator: Find the Day of the Week for Any Date

Weekday Calculator: Find the Day of the Week for Any Date

What day of the week were you born? When is Thanksgiving this year? What day does Christmas fall on? Our Weekday Calculator instantly tells you the day of the week for any date in history or the future. Using Zeller's congruence and validated algorithms, it accurately determines weekdays for dates from 1753 to 2399, covering the full range of the Gregorian calendar.

Calendar showing days of the week

How Weekday Calculation Works

Zeller's congruence is a mathematical formula that calculates the day of the week for any given date. It uses the year, month, and day to compute a value between 0 (Saturday) and 6 (Friday), with each number corresponding to a specific weekday. The formula accounts for leap years and the fact that months have different lengths.

For quick mental calculation, the Doomsday method (developed by John Conway) provides a simpler approach: memorize the day that certain dates fall on each year (4/4, 6/6, 8/8, 10/10, 12/12, and others), then calculate forward or backward from those anchor points.

Using the Weekday Calculator

Select a date using the date picker or enter the year, month, and day manually. The calculator shows the day of the week, the day of the year (1-365 or 1-366 for leap years), the week number of the year, whether it is a leap year, and how many days remain in the year.

The calculator also shows the dates of Easter Sunday for any year and the dates of US Thanksgiving (fourth Thursday in November) for easy reference.

Calendar planning and date selection

Key Calendar Facts

Leap Years

A year is a leap year if: divisible by 4 (2024 is a leap year), but not if divisible by 100 (2100 is not a leap year), unless also divisible by 400 (2000 was a leap year). Leap years add February 29, shifting all subsequent dates by one weekday.

Day Repetition

Dates repeat on the same weekday every 28 years in the Gregorian calendar cycle. For example, January 1, 2024 was a Monday, and January 1, 2052 will also be a Monday. This 28-year cycle helps in planning recurring events.

Year Types

Common year: 365 days, 52 weeks + 1 day. Leap year: 366 days, 52 weeks + 2 days. This is why weekdays shift by one day each common year and by two days after a leap year.

Interesting Historical Dates

  • January 1, 2000: Saturday (a leap year, the start of the 21st century)
  • July 20, 1969: Sunday (Apollo 11 moon landing)
  • December 7, 1941: Sunday (Pearl Harbor attack)
  • November 22, 1963: Friday (JFK assassination)
  • September 11, 2001: Tuesday (9/11 attacks)
  • Your birth date: Find out what day you were born

Real-World Example

What day of the week is Christmas 2026? December 25, 2026:

  • Using the calculator: December 25, 2026 is a Friday
  • Implication: Christmas falls on a Friday, making it a 3-day weekend for many workers
  • New Year's Day 2027: January 1, 2027 is also a Friday

What about leap year day 2028? February 29, 2028 is a Tuesday. Any wedding anniversary falling on February 29 would be celebrated on February 28 or March 1 in non-leap years.

The day of the week for January 1 of any year can be used to create an entire year calendar. January 1, 2026 is a Thursday, so 2026 is a common year starting on Thursday.

Start Calculating

Use our Weekday Calculator below to find the day of the week for any date. Also check our Date Difference Calculator for calculating date spans and our Business Days Calculator for working day calculations.